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OPTime User`s Guide

1. Data Availability C Simple No available post preventive maintenance performance data This is for users who do not have actual performance data but wish to estimate optimal timing using estimated performance trends This method uses a simple point and click visual interface to define performance curve shapes before and after a preventive maintenance treatment application and can be used when performance data are not yet available Use the detailed approach to conduct complex analyses based on more extensive performance data actual or estimated Choose from a number of methods for defining performance curves including entering equation coefficients directly or fitting regression curves through entered performance data Figure C 4 Analysis Type Selection dialog box Step 3 Selection and Definition of Condition Indicators The Selection of Condition Indicators tab shown in figure C 5 provides controls that are used to define the condition indicators that define pavement performance The selected condition indicators should be those pavement characteristics that are measurable able to be tracked over time are indicative of pavement performance mostly functional performance and are specifically influenced by the application of the selected preventive maintenance treatment Surface Type The first input on this dialog box is the selection of the surface type that best represents the pavement of interest HMA Surfaced pavemen
2. Step 8 Definition of Benefit Weighting Factors If multiple condition indicators are selected an individual benefit is calculated for each condition indicator and they are all used to determine optimal treatment timing Applying a benefit weighting factor is a way of differentially weighting these individual benefits associated with the different condition indicators The Benefit Weighting Factors dialog box figure C 23 contains input boxes associated with each condition indicator All benefit weighting factors are entered as integers and must total to 100 before proceeding C 56 Optimal Timing of Preventive Maintenance Treatments Benefit Weighting Factors Benefit Weighting Factors If mutilple condition indicators are selected an individual benefit is calculated for each and they are all used to determine optimal treatment timing Weighting factors are used to differentially weight the individual benefits associated with the included condition indicators For consistency all benefit weighting factors must total to 100 HMA Surfaced Pavement Benefit Weighting Factors Click on the Conduct Analysis button to tun the analysis ESIA Benefit Weighting Condition Indicator Factors o o Composite index Roughness smoothness n oOo Tete TOTAL 100 Note the individual benefit weighting factors must total to 100 Close Workbook Figure C 23 Example of the Benefit Weighting Factors dialog box As an
3. use of a standard unit length such as 1 mile is appropriate C 50 Discount Rate The discount rate is used to translate post construction costs into equivalent present worth and future worth costs It is defined as the difference between the interest and inflation rates over a period of time and represents the real value or cost of money The interest rate is the nominal cost of money while the inflation rate represents the changing purchasing power of money Historically discount rates have ranged from 3 to 5 percent Therefore the default value is set at 4 0 percent in the OPTime tool Preventive Maintenance Treatment Cost Details The PM Treatments cost details tab see figure C 18 includes all of the controls required to define the preventive maintenance treatment costs as well as any costs associated with additional maintenance Preventive Maintenance Treatment Costs The treatment unit cost is entered in the Treatment Unit Cost input box The assigned area or length units match those defined in the General Inputs area The computed total treatment cost is then displayed directly below as the Total Computed Treatment Cost In the life cycle cost analysis this total computed treatment cost is applied at the treatment application age associated with a given timing scenario Routine Maintenance Costs at Indicated Years If the costs of routine reactive maintenance are included in step 4 of the analysis setup the user also
4. In addition to defining do nothing performance relationships the user must define relationships that describe how the pavement is expected to perform after a preventive maintenance treatment has been placed More specifically a separate performance relationship condition versus age needs to be defined for each unique combination of condition indicator and treatment application age For example if an analysis includes three condition indicators and five application ages 15 3 x 5 different performance relationships must be defined When using the Simple analysis approach the definition of post preventive maintenance performance is facilitated by allowing the user to define the starting condition ending condition and expected extension of life in relation to the do nothing curve However when using the detailed approach the user must define all do nothing and post preventive maintenance performance relationships by selecting an equation type and entering equation coefficients directly or by entering data points and fitting a regression equation through those points Benefit Cutoff Values Benefit cutoff values are user defined condition indicator levels that define the upper and lower limits of the calculated benefit areas That is no benefit area above the upper benefit cutoff value or below the lower benefit cutoff value is included in the total benefit area used in the analysis The upper and lower benefit cutoff values hav
5. mi 40 E V User delay costs associated with work zone PM Treatments Rehabilitation User Delay Cost Summary You have chosen to include the cost of rehabilitation that is needed at the end of the pavements life cycle Use the controls provided on this page to define the appropriate rehabiliation related costs Rehabilitation Related Costs Rehabilitation Activity Name AC Overlay Rehabilitation UNIT Cost in today s dollars 80 000 00 per mi TOTAL Computed Rehabilitation Cost 80 000 Figure C 19 Example of the Definition of Costs dialog box with the Rehabilitation tab visible C 52 User Delay Cost Details The analysis approach allows user costs associated with construction delay to be included In this analysis user costs are associated with operating vehicles in a construction zone and specifically include the delay costs due to reduced speed to enter the work zone perhaps even to come to a complete stop if queuing reduced speed through the work zone and use of alternate routes to avoid work zone The User Delay tab figure C 20 includes all of the controls required to compute the user delay costs Optimal Timing of Preventive Maintenance Treatments Definition of Costs Definition of Costs o Net Use the following controls to define the costs to be included in the analysis Use the available controls to define specific cost types and their details Selection of Cost Types General In
6. Data Entry dialog box shown in figure C 17 To define the current post preventive maintenance curve enter data points year and value in the table on the left side of the dialog box note that the entered year is in terms of the age since treatment application Up to 20 data points may be used to define the equation and the data may be entered in any age order as they will be sorted in ascending order upon exiting this dialog box Next select an appropriate regression equation type from the Equation Type list box See table C 3 for more details regarding the specifics of each equation type and for guidance on what model is best suited to the expected curve shape The R value is displayed on the chart to help the user determine which equation type is a best fit for the given data set Based on the chosen equation type the resulting post preventive maintenance curve is displayed in the chart area on the right side of the dialog box The upper and lower benefit C 47 Regression Equation Data Entry Regression Equation Data Points Enter data points to define the treatment relationship described below Composite Index vs Age 2 G 8 gt 4 6 8 R 1 000 Treatment Age years Equation Type Power model Plot Curve Condition Indicator 1 Composite Index Treatment Slurry seal Relationship 2 of 3 for Composite Index Application Age 2 i Figure C 17 Example of the Regression Equation
7. Data Entry dialog box used to define a post preventive maintenance equation cutoff levels are also plotted as red lines on this same chart To update the chart after making changes to the entered data points click the _ Plst Curve button Step 7 Definition of Costs The Definition of Costs dialog box shown in figure C 18 provides controls that are used to define what types of costs are included in the analysis session The dialog box is divided into a cost type selection area a general inputs area and a series of tabs in which the individual cost details are defined C 48 Optimal Timing of Preventive Maintenance Treatments Definition of Costs Definition of Costs Net Use the following controls to define the costs to be included in the analysis Use the available controls to define specific cost types and their details Selection of Cost Types General Inputs V Treatment application costs Project Area or Length Discount Rate V Rehabilitation costs 1 mi 40 E M User delay costs associated with work zone PM Treatments Rehabilitation User Delay Cost Summary Enter treatment unit costs and estimated routine maintenance costs if applicable to be used in the analysis PM Treatment Costs Routine Maintenance Costs at Indicated Years Teamen Wann Select a year from the list and enter the associated cost Total Routine Slurry seal Year Maint Cost E Yearly Maintenance Cost Details T
8. The fifth column of the Effectiveness Summary table presents the computed expected life associated with each timing scenario As indicated previously the expected service life for the post preventive maintenance condition is the earliest age at which one of the post preventive maintenance condition indicator relationships reaches its individual governing benefit cutoff value In other words the presented expected life is the age at which one of the condition indicator relationships is assumed to reach a user defined failure level i e the governing benefit cutoff value Expected Extension of Life The final column of the Effectiveness Summary table presents the computed expected extension of life associated with each timing scenario These values are determined as the difference between the expected post preventive maintenance treatment life those values in column 5 of the table and the expected life of the pavement without a treatment represented by the original do nothing curve This calculated Expected Do Nothing Service Life is that value presented in the general feedback area of the Output Data worksheet The expected extension of life will therefore be negative for those timing scenarios where the application of a treatment causes the condition level to reach the governing benefit cutoff value sooner than what would have been achieved without applying the treatment i e the do nothing condition Condition Indicator Charts A seri
9. This table is comprised of six columns that include the treatment application age computed Effectiveness Index total benefit and EUAC values copied from the benefit and cost summary tables above an expected life and expected extension of life Effectiveness Index Each individual timing scenario is compared based on a normalized B C ratio referred to as the Effectiveness Index For each application age a B C ratio is computed internally as the ratio of the computed total benefit and EUAC values presented in columns 3 and 4 of this table Since the actual computed B C value has little meaning the individual computed B C ratios are normalized to a 0 to 100 scale by comparing all B C ratios to the maximum individual B C ratio i e that ratio that is associated with the optimal timing scenario This normalized value referred to as the Effectiveness Index is computed for each timing scenario using equation 1 _ B C moe max x100 Eq 1 where ElL Effectiveness Index associated with the i timing scenario dimensionless g C 62 B C Benefit to cost ratio associated with the i timing scenario B C max Maximum of all of the benefit to cost ratios associated with the different timing scenarios i Index associated with the current timing scenario Table C 5 illustrates this process by showing an example in which the analysis consisted of applying one chip seal in either year 1 2 3 4 5 or 6 i e six
10. a known condition failure level it is recommended that the governing benefit cutoff value be set equal to that treatment failure level Cost Data Types Up to four different cost types may be considered in any analysis session including preventive maintenance treatment costs the cost of a rehabilitation activity applied at the end of the estimated service life work zone user delay costs and routine maintenance costs Preventive maintenance treatment cost The treatment cost is the agency cost of applying the chosen preventive maintenance treatment This cost includes all design mobilization material construction and traffic control costs associated with the treatment application Rehabilitation cost The rehabilitation cost is the agency cost of a rehabilitation procedure that would be expected to be conducted when the applied preventive maintenance treatment is considered to be failed i e when the defined post preventive maintenance treatment relationship crosses the governing upper or lower benefit cutoff value Note that the timing of this rehabilitation cost is very much dependent on the selected governing benefit cutoff value Work zone user delay costs The methodology limits user costs to those associated with work zone delays i e the cumulative delay cost recognized by all users who travel through the preventive maintenance treatment work zone To compute user costs the main types of data that are requi
11. defines the associated cost details in the Routine Maintenance Costs at Indicated Years area of this dialog box The provided list displays all of the years for which maintenance costs are identified To enter the costs associated with each year click on a row in the table and enter the associated cost in the Total Routine Maintenance Cost at Year input box Undefined costs are interpreted as 0 costs in the analysis C 51 Rehabilitation Cost Details If rehabilitation costs are included in this analysis the Rehabilitation tab displayed in figure C 19 is enabled Two different input box values are entered on this tab First enter a descriptive name of the scheduled rehabilitation activity in the Rehabilitation Activity Name input box Next enter a unit cost for the activity in the Rehabilitation UNIT Cost input box the unit cost is entered in terms of the dimensional units defined in the General Inputs area The computed total rehabilitation cost is then displayed directly below the input box as the TOTAL Computed Rehabilitation Cost Optimal Timing of Preventive Maintenance Treatments Definition of Costs Definition of Costs o Ne Use the following controls to define the costs to be included in the analysis Use the available controls to define specific cost types and their details Selection of Cost Types General Inputs V Treatment application costs Project Area or Length Discount Rate V Rehabilitation costs 1
12. ha 10 0 Apply maintenance every 2 years Figure C 7 Preventive Maintenance Treatment Selection tab Treatment Selection This dialog box is used to select the one preventive maintenance treatment to be investigated within the analysis A default list of preventive maintenance treatments that reflects the chosen surface type HMA or PCC is provided within the PM Treatment Selection area of the dialog box See table C 2 for a summary of all of the default preventive maintenance treatments for each pavement type To add custom treatments to the treatment list select the Edit Treatment List option in the provided treatment list Selecting this option will open the Treatment List Management pop up dialog box shown in figure C 8 To add a new treatment to the list type the appropriate descriptive text in the text box at the bottom of the dialog and click the _444_ button C 27 Table C 2 Default preventive maintenance treatment types HMA Surfaced Pavements PCC Surfaced Pavements Crack filling crack sealing Crack sealing Fog seal Joint resealing Slurry seal Diamond grinding Scrub seal Microsurfacing Chip seal Thin overlay Ultrathin friction course HMA Treatment List Management Use the following controls to add or delete treatments from the treatment list To delete an item click on a treatment name in the list and click the Delete button Treatment List Crack sealing Fog seal Slurry seal Scru
13. the analysis Note the routine reactive maintenance costs are not summarized on this tab Optimal Timing of Preventive Maintenance Treatments Definition of Costs Definition of Costs Use the following controls to define the costs to be included in the analysis Use the available controls to define specific cost types and their details Selection of Cost Types General Inputs V Treatment application costs Project Area or Length Discount Rate V Rehabilitation costs 1 mi 40 E User delay costs associated with work zone PM Treatments Rehabilitation User Delay Cost Summary The following are the different costs that will be used in the analysis note all costs are in today s dollars PM Treatment Cost Summary User Cost Summary x Note all of the user cost numbers presented below are representative Treatment Name of year 0 values only i e both costs and number of vehicles Slurry seal affected will be inflated with time based on your inputs Total Computed Treatment Cost 18 000 No of Cost per Total Costs by Vehicle Category Vehicles Vehicle Category Rehabilitation Cost Summary Passenger Cars 4374 0 96 4 192 Rehabilitation Activity Name Single Unit Trucks 1 458 3 08 4 496 AC Overlay Combination Trucks 1 458 9 38 13 669 demin Harari ae dt S Total All Categories 7 290 22 356 Figure C 22 Example of the Definition of Costs dialog box with the Cost Summary tab visible
14. the condition indicator curve without the application of preventive maintenance i e the do nothing curve to the area associated with the condition indicator curve that is altered by the application of preventive maintenance For condition indicators that decrease over time e g serviceability friction or a typical composite index it is the area under the curve that defines benefit For condition indicators that increase over time e g roughness cracking rutting faulting and spalling it is the area above the curve that defines benefit The condition y axis boundaries used for the area computations are defined by the upper and lower benefit cutoff values both of which are described in more detail below The age x axis boundaries used for the area computations are year zero and the year at which the respective C 6 performance curve crosses the condition trigger level A more detailed discussion of the benefit computations is included in chapter 3 of the main report Condition Indicators A condition indicator is defined as any measure of condition used to define pavement performance One or more condition indicators may be selected for a given analysis session Each selected condition indicator should reflect the benefit of applying preventive maintenance and should be one for which monitoring data are available This is very important as all of the selected condition indicators will be used to collectively determine the benefi
15. timing EUAC versus treatment application timing Total benefit versus treatment application timing amp Microsoft Excel Example for Users Guide xls BAE File Edit View Insert Format Tools Chart Window Help A S RAA ARY a e i Q z fe A B C D E z G H J K E M N 0 xt Summary Chart 2 3 i n A Fan Effectiveness Index vs Application Timing 5 6 x 5 7 8 4 9 5 5 v c 10 5 2 1 2 ra isl E Ww 14 Ww T T T T T T T T T m5 1 2 3 4 5 1 2 3 4 5 1 Timing of First PM Application years Timing of First PM Application years 18 8 EUAC vs Application Timing Total Benefit vs Application Timing 51 10 000 4 00E 01 x 3 50E 01 z 3 000 w 3 006 01 6 000 2 S 250E 01 25 5 2 00601 26 4 000 1 50E 01 27 e 1 00601 2 i 5 00E 02 29 7 s 0 00E 00 i i r z 0 1 2 3 4 5 1 2 3 4 5 a 32 Timing of First PM Application years Timing of First PM Application years z M 4 gt ri Condition Indicator 2 Summary Charts lal 1 Ready NUM f Figure C 27 Example of the Summary Charts sheet included in an input output workbook C 66
16. timing scenarios Using the benefit and cost values assumed in table C 4 timing scenario 3 has the highest B C ratio and is thus assigned an Effectiveness Index of 100 An agency that generated these results could conclude that the optimal time to apply this preventive maintenance treatment is in year 4 but notice that the results from an application in year 3 are very similar Where there are minor differences in the Effectiveness Index there is more leeway in the timing of these treatments while larger differences in Effectiveness Index imply that the effects of deferring treatment application are more significant Table C 5 Example computation of effective indices for different treatment timing scenarios Year of Preventive Maintenance BENEFIT B COST C Benefit to Cost Effectiveness Application Overall Benefit EUAGC Ratio B C Index i 57 sow 0 00527 65 5 9 615 0 00681 a aa o tne soms oome s a sw vw w pos vs sss oosa x pe a For clarification the rows associated with the most effective application age i e the application age with an Effectiveness Index 100 are highlighted in yellow in all three summary tables When a computed B C ratio is negative that application age is labeled as Not C 63 Effective as this indicates that there would be a negative benefit associated with applying the treatment at that particular pavement age Expected Life
17. would be set to Decreasing as PCI is measured on a 0 to 100 index in which 100 represents a pavement with no distress The underlying analysis engine requires this input to correctly compute benefit As mentioned previously benefit is a function of the area under a curve when the condition indicator relationship is decreasing and the area above the curve when the relationship is increasing A more detailed explanation of the benefit computation is included in chapter 3 of the main report Lower and Upper Benefit Cutoff Values The lower and upper benefit cutoff values define the condition range that is used in the associated benefit calculations for a given condition C 24 indicator Since the analysis approach defines benefit as the area under a performance curve for a decreasing trend or the area above a performance curve for an increasing trend e g roughness these entered benefit cutoff values define the vertical boundary conditions in the area computations These entered values are expressed in terms of the respective condition indicator units In the OPTime tool the upper benefit cutoff value is always entered as the larger of the two benefit cutoff values i e upper benefit cutoff value is always greater than the lower benefit cutoff value The following sections provide more detailed explanations of the benefit cutoff values as they pertain to decreasing or increasing relationships Defining Benefit Cutoff Values for
18. 1 Entering Equations Directly The Equation Coefficient Definition area is displayed when the user chooses the Enter equation directly data entry method see figure C 16 Within this area of the dialog box the user is asked to select an equation type and define associated equation coefficients table C 3 summarizes the required equation coefficients associated with each available model type The defined post preventive maintenance performance relationship is plotted along with the defined benefit cutoff values on the condition indicator chart on the right side of each tab Note that the x axis of this chart represents the treatment age rather than the overall C 46 pavement age To update the chart after making changes to the equation coefficients click the Plot Curve button Method 2 Fitting a Regression Equation Through Entered Data The second method that may be used to define a post preventive maintenance performance relationship is to fit a regression equation through entered data points The Regression Equation Details area is displayed when the user chooses the Fit regression equation through data choice This area of the dialog box provides feedback to the user as the current regression equation type and the specific computed regression equation are presented To define the specific data points and regression equation type to be used click the Data Points button Clicking this button opens the Regression Equation
19. APPENDIX C USER S GUIDE FOR THE OPTIMAL PREVENTIVE MAINTENANCE TIMING ANALYTICAL TOOL OPTime INTRODUCTION Preventive maintenance is defined as a planned strategy of cost effective treatments applied to an existing roadway system that preserves the system retards future deterioration and maintains and improves the functional condition of the system without substantially increasing structural capacity 7 Although many agencies have implemented preventive maintenance programs there is still very little available guidance on determining the optimal timing of such treatments The analysis tool developed for this project is intended to bridge that gap by implementing a methodology for calculating optimal timing Although the analysis tool does not use a true optimization strategy 1 e all possible treatment application times are not analyzed it does provide a simple method for choosing the most effective treatment timing from a set of performance and cost data reflecting the application of a preventive maintenance treatment applied at different pavement ages This User s Guide is a hands on introduction to using the macro driven Microsoft Excel based analysis tool OPTime that was developed under National Cooperative Highway Research Program NCHRP project 14 14 Guide for Optimal Timing of Pavement Preventive Maintenance Treatment Applications It is not intended to answer all questions about the underlying analysis approac
20. Analysis Figure C 1 General structure of the analysis tool s user interface SunoliedDetinitian af Do Nothing Performance Curves C 16 Step 1 Introduction Dialog Box Once the analysis tool starts the first dialog box is the Introduction dialog box shown in figure C 2 The remainder of this section briefly describes the controls on this dialog box Optimal Timing of Preventive Maintenance Treatments Introduction Introduction This analytical tool is intended to be used to estimate the optimal timing of the first preventive maintenance treatment for a given pavement It was developed under NCHAF Project 14 14 Guide for Optimal Timing of Pavement Preventive Maintenance Treatment Applications This tool is designed for use by researchers or managers with access to preventive maintenance treatment performance and cost data It can also be used to analyze optimal timing scenarios based on expert opinion An associated User s Guide for this tool is found in Appendix C of the project s final report Follow the sequential steps of the program to setup and conduct the analysis and present intrepret the results Start by either choosing New to create a new session or Open to open a previously saved analysis session Edit the current analysis session note this is the default example session at start up Close Workbook Open Open a previously saved analysis session Source file for current analysis
21. Benefit EUAC Life yrs 25 a 7 805 26 Se 2a 28 Moai Input Interface Input_Data Output_Data Condition Indicai Ready Figure C 25 Example of an Output Data sheet included in an input output workbook Benefit Summary The benefit summary area of the Output Data sheet is comprised of individual condition indicator benefit values and a computed total benefit value associated with each application timing scenario The application age associated with the highest Effectiveness Index is highlighted in yellow in the benefit summary table Cost Summary The cost summary area presents the actual costs included in the analysis session Those cost types that were not chosen for inclusion in the analysis are presented as n a in this table The C 61 first column of this table includes the treatment application ages The next four columns include the costs in today s dollars associated with the preventive maintenance treatment user delay and other maintenance routine reactive maintenance The Total Present Worth column is computed as the sum of all of the present worth values of the individual included costs Finally the total present worth cost is translated into a EUAC based on the expected service life associated with each individual timing scenario application age Effectiveness Summary The final area of the Output Data worksheet is a summary of the relative effectiveness of each timing scenario
22. Bonici R Weighting Benefit Weighting gee Indicator Factor Factor Percentage ea M o 60 100 0 6 Roughness 30 100 0 3 3 6 smoothness Friction 47 tO 10 100 01 Selecting Appropriate Benefit Weighting Factors Selecting benefit weighting factors that correctly weight the different condition indicators is a very difficult task Because each condition indicator is plotted in different units a 10 percent increase in area associated with roughness is unlikely to have the same impact on performance as a 10 percent increase in friction area To choose meaningful benefit weighting factors it is recommended that many different combinations of benefit factors be evaluated to calibrate the resulting treatment effectiveness with actual expected performance data This process is not unlike the process used to determine the relative impacts of different distress values when they are incorporated into a composite index Extreme caution should be used when selecting benefit factors In fact as a first step it is recommended that each condition indicator be analyzed separately to get a better idea of the individual impacts of different timing scenarios on expected performance C 58 Conducting the Analysis The last step of the sequential interface the Benefit Weighting Factors dialog box includes a Conduct Analysis button Clicking this button will cause the analysis to be conducted During the analysis process a new work
23. Decreasing Relationships For relationships that decrease over time the lower benefit cutoff value represents a condition level indicative of a failure condition level for both the do nothing and treatment performance curves some may interpret this failure level as a rehabilitation trigger level For a single condition indicator the pavement age at which the do nothing curve intersects this lower benefit cutoff value is the upper age boundary in the x direction used in the computation of the do nothing benefit area Likewise the pavement age at which the post preventive maintenance relationship intersects the lower benefit cutoff value is the upper age boundary used in the computation of the post preventive maintenance benefit area associated with a chosen timing scenario When more than one condition indicator is used within an analysis session all individual condition indicator upper age boundaries are compared and the earliest age is set as the upper age boundary for all condition indicators That is as soon as one condition indicator reaches a failed condition benefit is no longer computed For decreasing relationships using an upper benefit cutoff value is a way to cap the benefit area That is the user may decide that even though conditions rise above a certain C 25 defined level e g greater skid resistance the additional benefit may not be necessary and thus should not be credited in the benefit calculations D
24. Maintenance Treatment Selection and Routine Reactive Maintenance Program Definition areas C 26 Optimal Timing of Preventive Maintenance Treatments PM Treatment Selection Preventive Maintenance Treatment Selection Use these controls to setup your optimal timing experiment In addition to selecting the treatment of interest you may choose to include additional routine reactive maintenance that is expected to affect the analysis PM Treatment Selection HMA Select the ONE treatment for which you would like to investigate initial application timing scenarios Slurry seal T Selected Treatment Initial Application Ages Next define the initial application ages that will be compared in the analysis Note ages may be entered as spectic values comma separated or age ranges hyphen separated see the example syntax below 0 2 5 Example An analysis of a treatment applied in years 3 4 5 7 and 8 is entered as 3 5 7 8 V Include routine reactive maintenance if selected the costs will be included in the analysis Routine Reactive Maintenance Program Definition Use these controls to define a schedule of routine reactive maintenance activities i e although these activities do influence performance their timing will not be optimized Application Method Regular interval details Regular interval Application age range gt m Set regular application interval Stat ge End Age e m Specific years
25. b seal Microsurfacing Chip seal Thin overlay Ultrathin Friction course To add a new treatment to the list type the name below and click the Add button Add Figure C 8 Example of the Treatment List Management dialog box with the default HMA treatment list displayed To delete a treatment from list click on the item of interest and click the Pelete button Once the list is altered click the 9 button to close the dialog box Selection of Treatment Application Ages After selecting the treatment to investigate the next step in the definition of the analysis session is to define the treatment application ages to compare Input one or more comma separated application ages or hyphen separated age ranges in the input box provided in the Selected Treatment Initial Application Ages area of the dialog C 28 box For example entering 1 3 5 7 10 will investigate the effectiveness of the chosen treatment applied in years 1 3 5 7 8 9 and 10 Each of these timing scenarios is in terms of the age since the start of the do nothing curve Routine Reactive Maintenance Program Definition To provide more flexibility in the analysis method the user may specify the timing and cost of maintenance activities that are assumed to be more routine or reactive in nature An example of such an activity is pothole patching While the patching potholes does influence long term performance it does not fit the typical preventiv
26. book is created in the background in which all of the inputs and outputs associated with the current session are stored After the analysis process is complete a dialog box will appear which asks if the user wants to save the current analysis session results INPUT OUTPUT WORKBOOKS After an analysis is conducted all inputs and outputs of that session are compiled into a new Microsoft Excel workbook that may be named and saved Then from the Introduction dialog box the first step of the sequential session definition procedure any of these saved input output workbooks can be opened by clicking the _ Open button and selecting a valid workbook Each input output workbook is comprised of a worksheet summarizing inputs a worksheet summarizing outputs a condition performance relationship chart for each included condition indicator and a set of charts that summarize the output results Input Data Sheet The nput Data sheet see figure C 24 is a summary of all the inputs including cost details do nothing curve relationship details and post preventive maintenance treatment performance relationship details C 59 amp Microsoft Excel Book2 xls File Edit View Insert Format Tools Data Window Help S f Input Data Pavement Surface Type HMA Treatment Type Crack sealing Application Years 02 5 Expected Do Nothing Service Life yrs 20 0 72 000 5q yds 37 00 AG Overlay 1 00 10 000 Simple 20 20 Annual Disc
27. ce curve As the name indicates the value entered in the Pavement Age input box represents the pavement age rather than the treatment age i e the entered age is NOT the age since treatment application but rather it is the time since the start of the do nothing curve However for reference the associated age since treatment application i e treatment age is displayed in parentheses next to the Pavement Age input box The Pavement Age must fall between the age at treatment application and the ending point age The pass through point condition is entered in the Condition Level input box in the Define Pass Through Point area The entered condition level must fall between the starting point and ending point conditions Post Preventive Maintenance Curve Chart The current post preventive maintenance relationship is plotted along side its corresponding do nothing curve on the condition indicator chart on the right side of the dialog box Also included on the chart are the defined upper and lower benefit cutoff levels for reference the actual defined lower and upper benefit cutoff values are displayed below the chart To update the chart after making changes to any of the inputs click the _ Flot Curve button Contents of the Detailed Analysis Summary List In a Detailed analysis the summary list see figure C 15 displays detailed information about each defined performance relationship Specifically the columns of this displayed li
28. curity level to Medium 5 Click OK to close the Security dialog box 6 Click OK to close the Options dialog box If these instructions do not appear to be valid for Excel click on the Help menu and conduct a search for macro security Follow the subsequent instructions to set the macro security to medium Starting the Analysis Tool To start the analysis tool simply open the OPTime xls file like any other Microsoft Excel workbook Specifically this file may be opened by either double clicking on the file name after using Windows Explorer to locate the file or by opening the file using the File gt Open menu commands within Microsoft Excel C 11 Upon opening the file the standard Excel pop up dialog box should appear that contains the following warning about macros Macros may contain viruses It is always safe to disable macros but if the macros are legitimate you might lose some functionality Click the Enable Macros button to allow Excel to run the macros and open the analysis tool Upon opening the OPTime xls file the macro driven user interface will automatically present the Introduction dialog box SETTING UP AND CONDUCTING AN ANALYSIS SESSION Introduction This section provides the user with all of the information that is required to set up and conduct a typical analysis session It begins with an introduction to the types of data required for a typical analysis and follows with a detai
29. e For the Detailed analysis method the process used to define the post preventive maintenance performance curves is identical to the process used to define the do nothing curves The first step is to choose the method for defining the do nothing performance relationship As with the definition of do nothing curves either an equation type and known equation coefficients may be entered directly or a regression equation may be fitted though entered data points C 45 Optimal Timing of Preventive Maintenance Treatments Treatment Relationship Details Treatment Performance Relationship Details Use the following controls to define post preventive maintenance performance relationships Cancel Condition Indicator Relationship Details Composite Index Relationship 1 of 3 associated with Composite Index Treatment Name Application Age Slurry seal 0 Performance Relationship 1 of 3 Data Enty Method Composite Index vs Age Enter equation directly Fit regression through data Equation Coefficients Equation type Power model Power Model 0 to 100 scale Equation Form y C m Age P c 100 m 0 1 P 2 52 m Equation Details y 100 000 100 x 2 520 Equation Trend Decreasing Plot Curve Figure C 16 Example of the Treatment Performance Relationship Details dialog box associated with a Detailed analysis Treatment Age years Method
30. e different meanings depending on whether the condition indicator curve is increasing or decreasing in nature The cutoff value on the upper end of the quality scale 1 e the upper benefit cutoff value for a decreasing curve and the lower benefit cutoff value for an increasing curve provides a cap or benefit ceiling on the quality that is credited to the treatment application Conversely on the lower end of the quality scale the benefit cutoff value often referred to as the governing benefit cutoff value typically represents the condition level at which the treatment is considered failed and requires either an additional preventive maintenance treatment or rehabilitation activity In contrast to the benefit cutoff value on the upper end of the quality scale the governing benefit cutoff value is the lower benefit cutoff value for a decreasing curve and the upper benefit cutoff value for an increasing curve For any analysis it is recommended that agencies select benefit cutoff values that most closely reflect their current maintenance and rehabilitation policies For example if an agency typically only applies one preventive maintenance treatment in the life of a pavement then the governing benefit cutoff value should be equal to the pavement failure level as a major rehabilitation is most likely be the next pavement treatment In contrast if an agency typically applies a second preventive maintenance treatment after the first application reaches
31. e governing condition for increasing relationships while the lower benefit cutoff value is the governing condition for decreasing relationships To define the curve s ending point enter the expected age in years at which the curve is to intersect the governing upper or lower benefit cutoff value For convenience the governing benefit cutoff value is displayed directly above this input box used to enter the Age at upper or lower benefit cutoff value C 31 Defining the Pass Through Point The final step in defining the do nothing curve is to define a third point for the curve to pass through This point should have an age that is between time zero and the ending point age and a condition that is between the starting point and ending point conditions Enter the specific pass through point age and condition in the appropriate input boxes within the Define Pass Through Point area of the dialog box Do Nothing Curve Chart The defined do nothing performance relationship is plotted along with the defined benefit cutoff values on the condition indicator chart on the right side of each tab For reference the actual defined lower and upper benefit cutoff values are displayed below the chart To update the chart after making changes to any of the inputs click the _ PlotCurve button It is important to note that the shape of a do nothing curve is determined automatically by the analysis tool Specifically an increasin
32. e maintenance model as it cannot be conducted until after the distress appears i e its timing cannot be truly optimized To include such activities in the analysis the specific maintenance timings years of application and costs are required to be defined by the user To estimate and enter a detailed routine maintenance schedule click the check box that says Include routine reactive maintenance if selected the costs will be included in the analysis After making that selection either define the additional maintenance timing schedule in terms of a Regular interval or Specific years An example of a regular interval would be every 2 years starting at year 1 and ending at year 9 i e maintenance applied in years 1 3 5 7 9 Use the provided input boxes to define such an interval Defining specific years is similar to entering treatment application ages All specific years are either entered as comma separated individual ages or hyphen separated age ranges For example entering 1 3 4 6 8 10 schedules additional maintenance in years 1 2 3 4 6 8 and 10 The user is asked to define the expected costs associated with each of the defined years in a later step of the analysis session setup process C 29 Step 5 Definition of Do Nothing Performance Relationships In this step all of the do nothing performance curves associated with the selected condition indicators are defined A do nothing curve represen
33. ected data that they can analyze The major difference between the two approaches is the complexity of how both do nothing and post preventive maintenance performance curves are defined The Simple approach allows the user to define the do nothing relationship in terms of a starting condition the age at which the curve is expected to intersect the governing benefit cutoff value and the coordinates of one point which the curve is to pass through Post preventive maintenance performance relationships are defined in terms of an initial condition value expected extension of life in relation to the do nothing curve and the coordinates of one pass through point In contrast when using the Detailed approach the user must define all do nothing and post preventive maintenance performance relationships by either entering the type of equation and its coefficients or by entering data points and fitting a regression equation through those points Use the controls on the Analysis Type Selection dialog box shown in figure C 4 to choose the appropriate analysis type that best suits the available data and analysis purpose Optimal Timing of Preventive Maintenance Treatments Selection of Analysis Type Analysis Type Selection Start your analysis by choosing either a Detailed actual data driven or Simple expert opinion driven analysis type Both analysis types are explained below Click on the Next button to continue with the analysis setup
34. ed equation does not match this expected equation trend Equation Coefficients After selecting an appropriate equation type the Coefficients area will display input boxes for the required coefficients Define required coefficients by entering values in the provided input boxes See table C 3 for a summary of the required equation coefficients associated with each available model type Compiled Performance Relationship When the equation is defined the compiled performance equation is displayed in the Equation Details area of the current tab After making changes to the equation coefficients click the _Plst Curve button to update the equation details displayed in this area Do Nothing Curve Chart The defined do nothing performance relationship is plotted along with the defined benefit cutoff values on the condition indicator chart on the right side of each tab For reference the actual defined lower and upper benefit cutoff values are displayed below the chart To update the chart after making changes to the equation coefficients click the Plot Curve button thod 2 Fitting a Regression Equation Through Entered Data The second method used to define a do nothing performance relationship is the fitting of a regression equation through entered data points The Regression Equation Details area is displayed when the user chooses the Fit regression equation through data choice see figure C 11 This area of the dialog box display
35. efining Benefit Cutoff Values for Increasing Relationships When a relationship increases over time the upper benefit cutoff value is assumed to represent a failure condition level for both the do nothing curve and the treatment performance curves For a single condition indicator the pavement age at which the do nothing curve intersects this upper benefit cutoff value is the upper age boundary in the x direction used in the computation of the do nothing benefit area Likewise the pavement age at which the post preventive maintenance relationship intersects the upper benefit cutoff value is the upper age boundary used in the computation of the post preventive maintenance benefit area associated with a chosen timing scenario For increasing relationships the lower benefit cutoff value represents a way to cap the benefit area That is the user may decide that even though conditions are observed to fall below a certain defined level e g smoother roads reduced IRI the additional benefit may not be necessary and thus should not be credited in the benefit calculations Step 4 Preventive Maintenance Treatment Selection The Preventive Maintenance Treatment Selection dialog box shown in figure C 7 provides controls used to choose the preventive maintenance treatment being analyzed and define the timing of any additional routine maintenance to be included in the cost analysis The dialog box is divided into the PM Preventive
36. equate surface friction is an important safety concern Therefore the effectiveness of a preventive maintenance treatment may be tracked in terms of its influence on friction Friction is commonly measured in terms of a friction index or skid number a characteristic that typically decreases over time See the Composite index explanation in the HMA surface section above The prompt sealing of cracks on PCC pavements can reduce the deterioration of those cracks over time Therefore some users may wish to track the typical deterioration severity level of cracks over time This crack deterioration would most likely be measured in terms of a length of cracking of a particular severity level over time As crack and joint sealing are effective at reducing the amount of water that infiltrates the PCC pavement structure these treatments can have a significant influence on the development of transverse joint faulting Therefore faulting may be used as a performance measure Transverse joint faulting is typically measured in terms of average faulting which is expected to increase over time Effective joint and crack sealing reduces the infiltration of water and incompressible material into joints and cracks thereby reducing the development of joint spalling or joint deterioration Joint spalling is commonly measured in terms of the amount of spalling number of joints or percentage of total joints of a particular severity level See the Rough
37. es of charts are included in the input output workbooks to visually present the expected condition indicator relationships associated with the most effective timing scenario A separate chart is included for each condition indicator included in the analysis session The example plot C 64 shown in figure C 26 illustrates a case in which the most effective timing scenario occurs when a preventive maintenance treatment is applied at a pavement age of 5 years Ed Microsoft Excel Example for Users Guide xls File Edit View Insert Format Tools Chart Window Help DeWea Say BBS S 2 Roughness Smoothness vs Age Application Age 5 v f a i Q A 7 A v a l a 3 i c Do Nothing The Best Treatment Application LowerBenefit Cutoff Value Upper Benefit Cutoff Value M 4 gt Condition Indicator 1 Condition Indicator 2 Summary Charts Ready Figure C 26 Example of a Condition Indicator sheet included in an input output workbook C 65 Summary Charts Sheet The final worksheet in each input output workbook is the Summary Charts sheet see figure C 27 This sheet contains four charts that summarize the data presented in the Effectiveness Results table on the Output Data worksheet Specifically the following four summary plots are included Effectiveness index versus treatment application timing Extension of life versus treatment application
38. evel input box For convenience the specific condition indicator units associated with the entered condition level are displayed directly above this Initial condition level input box C 30 Optimal Timing of Preventive Maintenance Treatments Definition of HMA Do Nothing Curves Definition of HMA Do Nothing Performance Curves Use the following controls to define the do nothing performance associated with each included condition indicator The do nothing curves define the expected performance of this pavement if no treatment is applied Comp Index Roughness Use these controls to define the do nothing curve for the user defined composite index Do Nothing Curve Definition Composite index units Oto 100 scale Composite Index vs Age Initial condition level 100 Lower benefit cutoff value 50 Age at lower benefit cutoff 15 years Define Pass Through Point 0 to 100 scale Specify a point for the curve to pass through Age 10 pears Condition level 80 Age years Equation Trend Decreasing t a Benefit cutoff values Lower 50 Upper 100 Figure C 9 Example of the Definition of Do Nothing Curves dialog box Simple Analysis Defining an Ending Point The ending point for a given do nothing curve is defined as the time at which the do nothing curve is expected to intersect the governing benefit cutoff value level Recall that the upper benefit cutoff value is th
39. example assume that a particular preventive maintenance treatment timing resulted in individual percent increases in benefit values of 27 percent for rutting 12 percent for roughness IRI and 47 percent for friction That is the preventive maintenance treatment application resulted in an increase of 27 percent over the rutting do nothing benefit area 12 percent over the IRI do nothing benefit area and 47 percent over the friction do nothing benefit area The benefit weighting factors are then used to combine these individual increases in benefit area into one overall increase in benefit area Using respective benefit weighting factors of 60 30 and 10 note these factors all add to 100 overall benefit contributions are determined by multiplying the benefit weighting factor percentages by the individual benefit values e g for rutting 27 percent 60 100 16 2 percent The total overall benefit contribution is then the sum of those C 57 values calculated for each individual condition indicator therefore in this example the total overall benefit contribution is 24 5 percent While by itself this total benefit value is essentially meaningless total benefit values computed for different timing scenarios can be used to compare the effectiveness of the different timing scenarios A summary of this example is presented in table C 4 Table C 4 Example computation of overall benefit Assigned Individual Benefit Overall Benefit Condition
40. g directory on the computer s hard drive that will store the analysis tool workbook 2 Copy the OPTime xls file from the enclosed CD ROM to the newly created directory To effectively use this analysis tool continued administrative privileges are needed for the created directory so that files can be saved to that directory as necessary Preparing the Microsoft Excel Environment The OPTime analysis tool is a Visual Basic Application VBA driven Microsoft Excel workbook To facilitate the entry of data a user friendly dialog box driven user interface has been incorporated to give the feel of a stand alone software program However this tool differs from stand alone software in that it must be opened within Microsoft Excel Because this C 10 analysis tool is driven by many macros a series of commands and functions stored in a Microsoft Visual Basic code module Microsoft Excel must be set up to allow these macros to run To set security to an acceptable level complete one of the following sets of steps From the Tools menu 1 Under the Tools menu click Macro 2 Click Security from the Macro submenu 3 Under the Security Level tab set the macro security level to Medium 4 Click OK to close the Security dialog box From the Options menu 1 On the Tools menu click Options 2 Click the Security tab 3 Click on the Macro Security button 4 Click the Security Level tab and then set the macro se
41. g do nothing equation is plotted by fitting a second order polynomial curve through the defined points In contrast a decreasing do nothing equation is plotted by fitting a power model curve through the defined points The typical shapes of these curves as well as the equation form are discussed in more detail in the next section Defining Do Nothing Relationships Under the Detailed Analysis Method The dialog box used to define do nothing relationships in the Detailed analysis is shown in figure C 10 In this dialog box a separate tab is displayed for each selected condition indicator included in the analysis session The same controls used to define the do nothing performance relationship are provided on each tab Selecting a Data Entry Method The first step is to choose the method used to define the do nothing performance relationship As previously indicated there are two options to define performance curves in the Detailed analysis method selecting an equation type and entering C 32 Optimal Timing of Preventive Maintenance Treatments Definition of HMA Do Nothing Curves Use the following controls to define the do nothing performance associated with each included condition indicator The do nothing curves define the expected performance of this pavement if no treatment is applied Definition of HMA Do Nothing Performance Curves Comp Index Roughness Use these controls to define the do nothing curve for the
42. g of the unit list associated with the Composite Index To add new units to the unit list type the appropriate descriptive text in the text box at the bottom of the dialog and click the _ Add button to add the text to the unit list To delete an item from the unit list click on the item of interest in the unit list and click the Delete button Once any unit list editing is completed click the __ button to close the Unit Management dialog box C 23 Unit Management Composite Index Use the following controls to add or delete unit descriptions from the unit list To delete an item click on a unit description in the list and click the Delete button Unit List Oto 100 scale Oto 10 scale Delete To add 4 new unit description to the list type the unit name below and click the Add button Add Figure C 6 Example of the Unit Management dialog box Trend Over Time The Trend Over Time field is an indication of the expected performance relationship trend over time For a given condition indicator select Increasing or Decreasing to coincide with the specific chosen units For example if Cracking were chosen as a condition indicator and the associated units are set to Length of Cracking ft the Trend Over Time input would be set to Increasing as the total observed length of cracking is expected to increase with time In contrast if PCI were chosen as a composite index the Trend Over Time
43. h as the analysis approach is described in much greater detail in chapter 3 of the main report However it does provide detailed information organized into the following five areas Analysis tool capabilities This section describes the capabilities and intended use of the OPTime analysis tool Key concepts of the methodology For quick reference this section summarizes many of the important terms that are encountered during the setup and conduct of an analysis session C 2 Getting started General system requirements and step by step procedures for getting started using the tool Setting up and conducting an analysis session This section starts with a discussion of the types of data needed to successfully define all required outputs in the analysis methodology The second part of this section walks a user through the analysis tool s user interface and the step by step procedure for setting up and conducting an analysis session Input Output workbooks Explanation of the produced output workbook that stores a summary of all defined inputs and the analysis output results ANALYSIS TOOL CAPABILITIES The primary purpose of this analysis tool is to enable pavement preservation engineers to analyze historical preventive maintenance related performance and cost data in order to determine the optimal timing of a given preventive maintenance treatment However it is recognized that agencies are in diffe
44. hat condition indicators are available to define performance Table C 1 summarizes brief descriptions of the default condition indicators and their typical units In addition to these default choices two user definable condition indicator fields are provided so that a user can define custom condition indicators that better measure the effectiveness of a particular preventive maintenance treatment C 21 Table C 1 Summary of default condition indicators included in the analysis tool Surface Type Condition Indicator Composite index Nonload related cracking Load related cracking Oxidation Raveling Rutting Roughness Smoothness Composite index Cracking deterioration Faulting PCC Joint Spalling HMA Roughness Smoothness Friction Description Many agencies use composite indices to track pavement performance over time Examples include a general cracking index or pavement condition index PCI Many of these decrease over time and are measured on scales such as a 0 to 100 0 to 10 or 0 to 5 The sealing or rejuvenating nature of many surface treatments can reduce the development of environmental or moisture related cracking This nonload related cracking measure reflects that benefit and would likely be measured in terms of the amount of cracking Preventive maintenance treatments such as crack sealing and thin surface seals are effective at keeping the pavement structure free from m
45. he post preventive maintenance curve is expected to intersect the governing benefit cutoff value level Recall that the upper benefit cutoff value is the governing condition for increasing relationships while the lower benefit cutoff value is the triggering condition for decreasing relationships The values reflecting the associated do nothing curve ending point i e the governing benefit cutoff level and the age at which the associated do nothing curve intersects that cutoff level are provided as reference points for the post preventive maintenance relationship In the Simple analysis method the curve s ending point is defined by entering an extension of life in years that is expected as a result of the preventive maintenance treatment application This extension of life is the expected difference in years between the ages when the post preventive maintenance and do nothing curves cross the governing benefit cutoff condition For example if the post preventive maintenance and do nothing curves are expected to intersect the governing benefit C 42 cutoff value at years 18 and 16 respectively enter a 2 years in the Expected extension of life input box 1 e the extension of life is 18 16 2 years Defining the Pass Through Point The final step in defining the post preventive maintenance curve is to define a third point for the curve to pass through This point is necessary as it defines the shape of the performan
46. hes its individual governing benefit cutoff value Continuing the previous example assume that for a particular timing scenario the rutting cracking and smoothness post preventive maintenance C 8 curves reach their governing benefit cutoff values at 20 22 and 24 years respectively For this timing scenario the expected service life and corresponding analysis period is therefore 20 years since that is the youngest age of all of the triggering conditions Just as with the do nothing condition this expected post preventive maintenance service life is the upper boundary condition in the x direction i e areas are only computed for the x range between 0 and 20 years Benefit Weighting Factors When more than one condition indicator is chosen to represent pavement performance in a given analysis a method is required for combining the computed individual benefit values associated with each condition indicator Benefit weighting factors are user chosen integer values between 0 and 100 that are defined to accomplish this task These values are weighting factors in that all defined benefit weighting factors must add to 100 The contribution to overall benefit associated with a given condition indicator is determined by multiplying the proportional weighting factor i e the entered weighting factor divided by 100 by the computed individual benefit value 1 e the computed percent in individual benefit area associated with the given cond
47. ition indicator In a sense benefit weighting factors allow the user to define a custom composite index in that the weighting factors determine how much impact each condition indicator s benefit has on the total benefit used in the analysis While the approach is simple it is very important for a user or agency to conduct many analysis trials in an effort to gain a good understanding of how expected individual benefit areas should be weighted GETTING STARTED System Requirements and Recommendations To effectively use this analysis tool an IBM compatible industry standard personal computer with the following minimum characteristics is required C 9 Intel Pentium Pro Pentium or 486 PC Microsoft Windows 98 Windows 95 Windows NT 4 0 or newer operating system Minimum of 32 Mb of RAM Pointing device CD ROM drive Super video graphics adapter with at least 800 x 600 resolution with 256 colors Note for best viewing set the display resolution to 1024 x 768 with High 16 bit color selected Microsoft Excel Note this analysis tool was developed under the Microsoft Excel 2002 Copying the Analytical Tool to Your Computer To use this analysis tool first copy the OPTime xls Excel workbook to your computer s hard drive Note you must have administrative privileges on your computer to accomplish this task To copy the file complete the following steps 1 Use Windows Explorer to create a new workin
48. lationships reaches its associated governing benefit cutoff value To determine the analysis period for a given timing scenario all condition indicator relationships are first looked at individually to determine the ages at which each curve reaches its respective preventive maintenance treatment failure level Expected Service Life of the Do Nothing Condition The expected service life for the do nothing condition is the earliest age at which one of the included condition indicator relationships reaches its individual governing benefit cutoff value i e the upper benefit cutoff value for increasing relationships and the lower benefit cutoff value for decreasing relationships For an example that includes rutting cracking and smoothness where each performance curve reaches its governing benefit cutoff value at 15 14 and 17 years respectively the overall do nothing curve expected service life for the analysis session is 14 years since that is the youngest age of all of the triggering conditions Note that this expected do nothing service life therefore is the upper boundary condition in the x direction i e for this example areas would only be computed for the x range between 0 and 14 years Expected Service Life of the Post Preventive Maintenance Condition The expected service life for the post preventive maintenance condition is the earliest age at which one of the post preventive maintenance condition indicator relationships reac
49. led step by step guide to using the analysis tool This section will help in making input related decisions while completing the analysis setup process Required Data Types Conducting a meaningful analysis requires the collection and representation of four primary types of data including do nothing curve relationships post preventive maintenance performance relationships upper and lower benefit cutoff values and cost information As previously stated the results of the analysis session are only as good as the quality of the defined inputs Do Nothing Curve Relationships Before the influence of a preventive maintenance application can be analyzed the analysis requires a baseline performance curve or curves from which the changes due to the application of preventive maintenance are measured The baseline performance curve of interest for a C 12 particular condition indicator is that performance curve condition indicator versus time expected if only routine maintenance were conducted on the pavement Such curves are referred to as do nothing performance curves The methodology requires that the user define a do nothing performance curve for each condition indicator that is included in the analysis A good source for this information is an existing pavement management system although users without access to such curves can easily be walked through a process of approximation Post Preventive Maintenance Performance Relationships
50. ndition indicator relationships are defined visually rather than through the definition of specific mathematical relationships As previously indicated this analysis tool allows a user to define performance relationships associated with different application timings of a given preventive maintenance treatment Based on those defined performance relationships the effectiveness of a treatment applied at a particular pavement age is determined as a function of computations of benefit and cost associated with each defined timing scenario Benefit is computed as a function of condition and time i e area under the condition versus age curve for decreasing equations while included costs are compiled as an equivalent uniform annual cost EUAC of all included treatment rehabilitation work zone user delay and additional routine maintenance costs To facilitate timing scenario comparisons benefit to cost B C ratios computed for each timing scenario are then normalized into an Effectiveness Index in which the largest B C ratio is equivalent to an Effectiveness Index of 100 The timing scenario with the largest B C ratio i e an Effectiveness Index of 100 is identified as the best most cost effective treatment timing of all of those investigated C 4 It should be noted that the computation of benefit is not limited to the inclusion of only one condition indicator in the analysis methodology The individual benefits associated with up to
51. ness Smoothness explanation in the HMA surface section above See the Friction explanation in the HMA surface section above C 22 To include a particular condition indicator in the analysis click on the condition indicator name or its associated check box to enable it To disable a previously selected condition indicator click again on the condition indicator name or check box To include one of the user definable fields first click the name to enable the condition indicator and then enter a descriptive condition indicator name in the text box directly to the right of the associated check box Each selected condition indicator should reflect the benefit of applying preventive maintenance and should be one for which monitoring data are available This is very important as all of the selected condition indicators are used collectively to determine the benefit associated with the application of the treatment It is also important to remember that do nothing performance curves must be defined for each condition indicator included in the analysis Condition Indicator Units For each condition indicator select the appropriate measurement units from the provided list If the default list does not contain the desired units select the Edit Unit List option to add additional unit definitions When editing the current unit list the Unit Management pop up dialog box will appear figure C 6 illustrates an example of the alterin
52. nine hot mix asphalt HMA related condition indicators seven standard and two user defined fields or up to eight portland cement concrete PCC related condition indicators six standard and two user defined fields may be included in the overall analysis Benefit values associated with each included condition indicator are then combined into an overall Total Benefit using user defined weight values benefit weighting factors The detailed procedures for computing individual condition indicator benefits total overall benefit costs and Effectiveness Indices are all described in chapter 3 of the main report The output of any analysis session includes the following Benefit Summary Summary of both individual benefits benefit values associated with each included condition indicator and total benefit computed for each timing scenario The timing scenario with the largest associated B C ratio is highlighted Cost Summary Summary of all included treatment rehabilitation work zone user delay and additional routine maintenance costs expressed in present worth dollars All computed present worth dollars are then compiled into an EUAC so that timing scenarios resulting in different analysis periods may be compared directly the user has the option to include or exclude any of these cost types from the analysis Effectiveness Summary The B C ratios are normalized and reported in terms of Effectiveness Indices That timing scenario
53. nothing curve expected as a result of the preventive maintenance treatment application Pass Through Point tThe last two columns in the list defines the user defined pass through point used to determine the post preventive maintenance equation C 39 Optimal Timing of Preventive Maintenance Treatments Treatment Performance Summary Treatment Performance Relationship Summary List The list below summarizes all of the unique post preventive maintenance performance relationships that you indicated you would define To define a specific performance relationship select a row from the list and click the Edit Details button Performance Relationship Summary List Simple Analysis Treatment Name Slurry seal Index Condition Indicator Composite Index Composite Index Composite Index Roughness smoothness Roughness smoothness Roughness smoothness Condition Values Cutoff Condition Indicator Units Oto 100 scale Oto 100 scale Oto 100 scale IRI in mi IRI infmi IRI in mi Application Year Extension Initial of Life yrs CILI Relationship 1 of total relationships e re Pass Through Point Pavement Age Condition Edit Details i Figure C 13 Example of the Treatment Performance Relationship Summary List associated with a Simple analysis To define the specifics of a particular post preventive maintenance relationship first click on that row in list and then click the dit Detail
54. nt information is provided about the current performance relationship for which the details need to be defined This information includes the condition indicator name treatment name relationship details and the current application age Performance Relationship Area The details of the current post preventive maintenance relationship are defined using the controls in the lower left area of the dialog box As with the definition of do nothing curves under the Simple analysis method three points on a curve define post preventive maintenance relationships a starting point an ending point and a pass through point To help in the definition of these three points the expected equation C 41 trend i e the user defined trend over time associated with the current condition indicator is displayed in the lower left corner of each condition indicator tab Defining a Starting Point The starting point for a given do nothing curve is defined by the condition level that is expected as a result of the treatment application i e the condition immediately after treatment application This value is entered in the Tnitial condition level input box For convenience the specific condition indicator units associated with the entered condition level are displayed directly above this Initial condition level input box Defining an Ending Point The ending point for a given post preventive maintenance curve is the time at which t
55. nted relationship The two methods available include Direct Coefficients i e choosing an equation type and defining the appropriate equation coefficients or Regression i e defining data points and fitting a regression equation through those points C 44 Application Year The application age for which the current performance relationship is applicable Defined Relationship The defined post preventive maintenance relationship associated with a given combination of condition indicator and treatment application age Not Defined is displayed in this data field for those post preventive maintenance relationships that have not yet been defined To define a particular post preventive maintenance relationship equation first click on that row in the list and then click the Edit Details button Clicking the Edit Details button opens the Treatment Performance Relationship Details dialog box see figure C 16 Use the controls on this box to define the details of the current post preventive maintenance relationship The dialog box is divided into two different areas a feedback area at the top of the dialog box and the Performance Relationship details area The feedback area of the dialog box provides pertinent information about the current performance relationship for which the details need to be defined This information includes the condition indicator name treatment name relationship details and the current application ag
56. oisture infiltration thereby reducing load related cracking associated with the weakening of the pavement structure Therefore the user may want to track the development of load related cracking over time as a measure of the effectiveness of a particular preventive maintenance treatment As with non load related cracking load related cracking would most likely be measured in terms of the amount of cracking The sealing or rejuvenating nature of many surface treatments can significantly reduce the occurrence of oxidation and raveling Raveling is often reported as an area and severity level Although there is not currently a widely accepted measure of oxidation the user may want to consider the development of a subjective rating scale e g a scale of 0 to 5 Several preventive maintenance treatments may be used to correct rutting problems so rutting may be used as a performance measure Rutting is typically measured in terms of an average rut depth which is expected to increase over time Roughness typically increases over time and is often measured in terms of International Roughness Index IRI Some agencies prefer to characterize the measurement of surface characteristics in terms of smoothness instead of roughness A smoothness measurement is typically expected to decrease over time e g present serviceability index PSI is a subjective measurement on a 0 to 5 scale where 5 represents a perfectly smooth pavement Maintaining ad
57. on the selection of an equation type and the definition of equation coefficients are included below Equation Type Use the equation type list box to select an equation type for the current do nothing curve The five available equation types are as follows linear power model second order polynomial exponential and logarithmic Table C 3 presents detailed descriptions of each available equation type including the model form required coefficients the applicability of the model based on expected trends over time and some visual feedback demonstrating the typical curve shapes that are associated with the chosen model type Table C 3 Details of the equation types available for use in the analysis tool Applicable Equation Required Equation Example Curve Type Equation Form Coefficients Direction Shape s Linear y m Age b m b Increasing Power y C m Age C m P Decreasing Model Second y A Age B Age C A B C Increasing Order Polynomial u Logarithmic y A Ln Age B A B Increasing C 34 To facilitate the selection of an appropriate equation type the expected equation trend i e the user defined trend over time associated with the current condition indicator is displayed in the lower left corner of each condition indicator tab A warning is displayed if the defin
58. ount Rate er Treatment Cost 12 000 Rehabilitation Cost Not included User Cost Years Not included Di neetionn AA Ma gt DI Input Ready a DN he be al Data Output_Data Condition Indicator 1 _ Condition Figure C 24 Example of an Input Data sheet included in an input output workbook Output Data Sheet The Output Data sheet is a summary of all the outputs that were determined during the current analysis session see figure C 25 In addition to general feedback such as the pavement surface type treatment type treatment application years and the computed expected do nothing service life this data sheet contains a benefit summary a cost summary and an effectiveness summary C 60 Ed Microsoft Excel Example for Users Guide xls DRAA SRAY tee S z 2 W 4 10 e H File Edit Yiew Insert Format Tools Data Window Help Al X f B C D 5 Benefit Summary 10 Individual Benefit Summary 11 Benefit Ranking Factors gt Application Composite Roughness 2 13 oO 77403 002 ooo 4 2 f ooz 009 f 006 15 16 17 Cost Summary Other Application Treatment User Cost Maintenance Rehab Cost Total Present 18 Age yrs Cost PW PW Cost PW PW Worth EUAC 19 OO a00 22 356 44 421 86 777 7 805 20 18 491 21 493 962 44 421 85 366 7 678 21 22 gt Effectiveness Su Expected Application Effectiveness Expected Extension of 24 Age yrs Index Total
59. puts V Treatment application costs Project Area or Length Discount Rate V Rehabilitation costs 1 mi 40 z Ww User delay costs associated with work zone lik PM Treatments Rehabilitation User Delay Cost Summary Enter design traffic information and costs associated with user delays work zones The design traffic information is needed to compute the number of vehicles that pass through a work zone for a given year Design Traffic Delay Cost Rate Work Zone Related Information Initial ADT 10 000 veh day Passenger Cars Treatment name Slurry seal ADT growth rate 2 percent 11 50 hr Work zone start time 00am gt Bioatvess Simple zl Single Unit Trucks Work zone duration 12 hours Percentage ADT by vehicle type 18 50 hr Passenger Cars 60 Single Unit Trucks 20 Combination Trucks 20 Edit Hourly Traffic Distribution Avg additional delay time min veh by type Combination Trucks Passenger Cars 5 min veh 22 50 hr Single Unit Trucks 10 min veh Combination Trucks 25 min veh Figure C 20 Example of the Definition of Costs dialog box with the User Delay tab visible The inputs in this basic analysis are based on the method outlined in the 1998 FHWA report Life Cycle Cost Analysis in Pavement Design 23 To compute user delay costs the following inputs are required C 53 Design Traffic Information Input general traffic information such as initial ave
60. rage daily traffic ADT the expected annual growth rate in ADT and the expected ADT growth type either simple or compound Additionally define the percent ADT associated with passenger cars single unit trucks and combination trucks The Percentage ADT by Vehicle Type inputs are entered as integer values and all three must sum to 100 To define the specific percent of total day ADT associated with each clock hour of the day click on the _ Edit Hourly Traffic Distribution button This opens the Traffic Distribution Details dialog box displayed in figure C 21 All of these traffic inputs are used to compute the total number of passenger cars single unit trucks and combination trucks that will pass through a defined work zone Note the default hourly traffic distribution values shown in figure C 21 are the default values used in the MicroBENCOST life cycle cost software for rural roadways 23 Delay Cost Rate Delay cost rates for each vehicle classification must be entered in the appropriate input boxes The 1998 FHWA Report provides typical ranges of 10 to 13 for passenger cars 17 to 20 for single unit trucks and 21 to 24 for combination trucks 23 The default values used in the OPTime tool are the average values of each of these ranges These entered values are used to compute the total delay cost associated with each vehicle passing through the defined work zone C 54 Traffic Distribution Details Hourly Traffic Dist
61. reatment Unit Cost i i Year 18000 per mi Year 9 Total Computed Treatment Cost Total Routine Maintenance 18 000 Cost at Year 4000 Figure C 18 Example of the Definition of Costs dialog box with the PM Preventive Maintenance Treatments tab visible Selection of Cost Types The first step on this dialog box is to use the controls in the Selection of Cost Types area to select the cost types to be included in the analysis In addition to any routine reactive costs defined previously the following three different cost types are available Treatment application costs Treatment costs are agency costs associated with the construction of the preventive maintenance treatment Rehabilitation costs As it is widely held that preventive maintenance treatments delay the timing of more costly rehabilitation activities to include that potential long term life cycle cost impact the analysis tool allows the inclusion of a rehabilitation cost When C 49 rehabilitation costs are included a rehabilitation activity is assumed to be applied at the end of the preventive maintenance treatment s service life Recall that the end of the preventive maintenance treatment service life is the earliest age at which one of the post preventive maintenance performance curves associated with one of the included condition indicators reaches its governing benefit cutoff value User delay costs The methodology limits user costs to tho
62. red are information about expected traffic levels as well as work zone related information e g expected work zone duration and typical delay times encountered in the work zone Routine maintenance costs To be completely thorough in the representation of costs in this analysis the user has the option of including the costs associated with a defined routine maintenance schedule Examples of routine maintenance activities that fall under this cost type include pothole patching and crack sealing costs if the timing of first crack sealing is not the focus of the investigation C 15 Analysis Setup The user interface of the analysis tool is a series of sequential steps that must be completed to conduct the analysis Two parallel paths through the interface are provided based on whether the Simple or Detailed analysis type is selected An overall flow chart showing the general structure of the user interface is presented in figure C 1 Each step of the setup process is discussed in more detail in separate sections below Introduction Analysis Type Selection Simple Detailed Selection and Definition of Condition Indicators Preventive Maintenance Treatment Selection DetavedDetinition of Do Nothing Performance Curves SimelifieaDetinitian of Post Detaled Definition af Post PM Treatment Performance PM Treatment Performance Relationships Relationships Definition of Costs Definition of Benefit Ranking Factors Conduct
63. rent stages of developing pavement preservation strategies with many still in the early stages of collecting preventive maintenance related performance data Therefore flexibility is built into the tool with the inclusion of two parallel analysis methods simply referred to as Detailed and Simple methods used to compare preventive maintenance timing scenarios Both analysis types are briefly described below Detailed Analysis The main purpose of the Detailed method is to analyze actual or estimated data obtained from monitoring preventive maintenance treatment performance in the field over time Because actual field data is expected for this analysis method expected condition versus age relationships before and after preventive maintenance treatment applications must be defined by either selecting an equation type and entering C 3 known equation coefficients or by fitting a regression equation though entered condition versus age data points Simple Analysis When actual performance data are not available the Simple method is used to create and compare what if timing scenarios The user interface of the Simple method allows the estimation of performance relationships required by the analysis Performance relationships are more easily defined by choosing a starting condition level one condition versus age point for the curve to pass through and the expected extension of life at the governing benefit cutoff value Essentially co
64. ribution This list shows the percent distribution of average daily traffic ADT by hour 1200am 1 8 12 00pm 57 1 00am 15 1 00pm 64 2 00 a m Be 2 00 p m 6 8 3 00 a m 13 3 00 p m 7 3 4 00am 15 4 00pm 93 5 00 a m 18 5 00 p m 7 6 00am 25 6 00pm 55 700am 35 7 00pm 47 800am 42 8 00pm 38 900am 5 9 00pm 32 10 00am 54 10 00pm 26 11 00am 56 11 00pm 23 24 Hour TOTAL 100 00 Note the total hourly 4 ADT values must total to 100 Figure C 21 Example of the Traffic Distribution Details dialog box with default percentages shown Work Zone Related Information The work zone related information area is used to define the details of the project work zone The Work zone start time is the clock hour when the work zone is assumed to start The Work zone duration is the total number of hours that the work zone is expected to be active on the roadway i e the time from lane closures to time of opening to traffic These two inputs together are used to determine the number of vehicles that will be passing through the work zone Finally the Average additional delay time in minutes vehicle for each vehicle type is required to determine the effect of the work zone on each of the three vehicle categories C 55 Cost Summary The Cost Summary tab figure C 22 summarizes all of the preventive maintenance treatment rehabilitation and user delay costs that are selected for
65. rkbook You have indicated you wish to close the analysis workbook Choose one of the options below NOTE your inputs will only be saved if you run an analysis and save the outputs in a separate file Close the analysis workbook WITHOUT saving the current inputs as part of the workbook poe Return to the user interface to continue working Figure C 3 Closing the Analysis Workbook dialog box You may also exit the workbook by clicking close window box i e Ed in the upper right corner of most dialog boxes However recall that exiting the workbook via the close window box will close the workbook without saving any changes made to the inputs About Button Click on the bout button to view general information about the analysis tool Such information includes acknowledgements and contact information Help Button If at any point during the setup of the analysis session more detailed information associated with a dialog box s purpose controls or inputs is needed click on the provided i button to view specific help text Step 2 Analysis Type Selection As mentioned previously preventive maintenance timing scenarios may be compared using either a Simple or Detailed analysis type The Detailed approach is intended for those users that want to analyze actual condition data The Simple approach is intended for those users who would like to become familiar with the analysis concepts but do not have a lot of coll
66. ry dialog box shown in figure C 12 To define the current do nothing curve enter data points year and value in the provided tabular input boxes on the left side of the dialog Up to 20 data points may be used to define the equation The data may be entered in any age order as they will be sorted in ascending order upon leaving this dialog box C 36 Regression Equation Data Entry Regression Equation Data Points Enter data points in the grid below that will be used to define the do nothing condition indicator curve Note you do not have to enter points for every age Composite Index vs Age 2 p 8 k gt 10 15 R 2 1 000 Age years Equation Type Power model i Plot Curve Figure C 12 Example of the Regression Equation Data Entry dialog box Next select a regression equation type from the Equation Type list box The same equation types available for defining the equation directly are also available here i e linear power model second order polynomial exponential and logarithmic Table C 3 provides more details regarding each equation consider the following if additional guidance is needed 1 The Power model is only appropriate for relationships that decrease over time Additionally a point with an age of zero is required for this model type 2 The Logarithmic model will not accept a data point with an age of zero C 37 Based on the selected equation type the resul
67. s button This opens the Treatment Performance Relationship Details dialog box see figure C 14 Use the controls on this box to define the details of the current post preventive maintenance relationship The dialog box is primarily divided into two different areas the feedback area at the top of the dialog box and the Performance Relationship details area C 40 Optimal Timing of Preventive Maintenance Treatments Treatment Relationship Details Treatment Performance Relationship Details Use the following controls to define post preventive maintenance performance relationships ee Condition Indicator Relationship Details Composite Index Relationship 1 of 3 associated with Composite Index Treatment Name Application Age Slurry seal 0 Performance Relationship 1 of 3 Curve units Oto 100 scale Composite Index vs Age Initial condition level 100 Lower benefit cutoff value 50 Do Nothing age at lower cutoff 15 years Expected extension of life 1 Define Pass Through Point 0 to 100 scale Specify a point for the curve to pass through Pavement age 10 yrs Treat age 10 10 15 Condition level 90 Age years Do Nothing Post PM Equation Trend Decreasing ot Curve Figure C 14 Example of the Treatment Performance Relationship Details dialog associated with a Simple analysis Feedback Area In the feedback area of the dialog box pertine
68. s the current regression equation type and the specific computed regression C 35 Optimal Timing of Preventive Maintenance Treatments Definition of HMA Do Nothing Curves Definition of HMA Do Nothing Performance Curves Use the following controls to define the do nothing performance associated with each included condition indicator The do nothing curves define the expected performance of this pavement if no treatment is applied Comp Index Roughress Use these controls to define the do nothing curve for the user defined composite index Data Entry Method Enter equation directly Composite Index vs Age Fit regression equation through data Regression Equation Details Click the Data Points button to enter data points 2 G 8 gt gt Equation type Power model Computed Regression Equation y 100 000 048 x 2 322 10 15 R 2 1 000 Age years Equation Trend Decreasing Benefit cutoff values Lower 50 Upper 100 Figure C 11 Example of the Definition of Do Nothing Curves dialog box Detailed Analysis with the Regression Equation Details area displayed equation More specific details on how to define the specific data points and regression equation type are included below Entering Regression Data To enter specific data points and select the regression equation type to be used click the _ Dat Paints button This opens the Regression Equation Data Ent
69. se associated with work zone delays i e the cumulative delay cost recognized by all users subjected to the preventive maintenance treatment work zone Other common types of condition sensitive user costs e g vehicle operating discomfort and crash costs are not included because the range in condition is assumed to be relatively small for pavements that are candidates for preventive maintenance This cumulative delay cost is computed as a function of the average number of vehicles per day AADT work zone duration average vehicle delay time and cost per delay time per vehicle Use the Selection of Cost Types check boxes to select the cost types to include in an analysis Clicking on an already enabled cost type disables it Enabling a cost type causes its associated details tab at the bottom of the dialog box to become enabled While all three cost types are optional in that each can be disabled at least one of the cost types must be enabled the cost of preventive maintenance treatments is recommended before the analysis can continue General Inputs Two general cost related inputs the project size and discount rate greatly affect the calculated life cycle costs Project Area or Length Select a unit type from the list box and enter an appropriate project size related value as an integer in the input box These entered values allow the computation of total costs that feed into the life cycle cost analysis In many cases the
70. session Saved file Name None Default Example Session Saved file Path None Default Example Session Figure C 2 Introduction dialog box New Button Click the button to create a blank analysis session Open Button Data files used by the analysis tool are stored as separate Microsoft Excel workbooks Click the __ OPen button to open an existing previously saved analysis session and then select the named Excel workbook that houses the analysis session For reference the specific name and path of a file that has been opened will be displayed at the bottom of this dialog After opening an existing session use the provided input interface controls to make appropriate changes to the session Close Workbook Button Click on the lse Workbook button to exit and close the analysis tool workbook Clicking this button will bring up the Closing the Analysis Workbook dialog box shown in figure C 3 The _ Exit land Cancel buttons provided on this dialog box are described below The Est button closes the analysis tool workbook i e OPTime x ls without saving any changes made to the current session Inputs are only saved as part of the new workbook that is created as a result of conducting an analysis session The _ Cancel button returns the user to the user interface The analysis tool workbook i e OPTime x s will not be closed and therefore any input changes will not be lost Closing the Analysis Wo
71. st of all of the post preventive maintenance performance relationships that must be defined before conducting the analysis session Each row in the displayed list is associated with each unique combination of chosen condition indicator and treatment application age For example if three condition indicators and five application ages are selected there will be 15 rows 3 x 5 in the summary list C 38 box The specific information displayed in the summary list is dependent on the selected analysis method Contents of the Simple Analysis Summary List When conducting a Simple analysis the summary list see figure C 13 displays detailed information about each defined performance relationship Specifically the columns of this displayed list present the following data Index A generic list index that shows the total number of relationships that need to be defined Condition Indicator The condition indicator associated with the current post preventive maintenance relationship Condition Indicator Units The user selected units associated with the condition indicator of the current relationship Application Year The application age for which the current performance relationship is applicable Condition Values The user defined initial condition and governing benefit cutoff values are presented here as feedback Extension of Life This column is the user defined extension of life in comparison to the associated do
72. st present the following data C 43 Optimal Timing of Preventive Maintenance Treatments Treatment Performance Summary x Treatment Performance Relationship Summary List The list below summarizes all of the unique post preventive maintenance performance relationships that you indicated you would define To define a specific performance relationship select a row from the list and click the Edit Details button Performance Relationship Summary List Detailed Analysis Treatment Name Slurry seal Application Index Condition Indicator Relationship Source Year Defined Relationship Composite Index Direct Coefficients y 100 000 100 x 2 520 Composite Index Regression y 100 000 238 x 2 322 Composite Index Regression y 100 000 1 068 x 1 604 Roughness smoothness Regression y 467 x 2 333 x 40 000 Roughness smoothness Regression y 267 x 2 2 667 0 40 000 Roughness smoothness Regression y 268 x 2 4 3 393 x 40 000 lt Relationship 1 of 6 amp 6 total relationships Edit Detak Figure C 15 Example of the Treatment Performance Relationship Summary List associated with a Detailed analysis Index A generic list index that gives and indication of the total number of relationships that need to be defined Condition Indicator The condition indicator associated with the current post preventive maintenance relationship Relationship Source The method used to define the prese
73. t associated with the application of the treatment Do Nothing Performance Curve The do nothing performance curve is the condition indicator versus age relationship that is expected in the absence of conducting any preventive maintenance activities on the pavement Note the do nothing curve by default does include the effects of routine maintenance Do nothing performance curves must be defined for each condition indicator included in an analysis Upper Benefit Cutoff Value The upper benefit cutoff value is the user chosen upper limit to the benefit area computation i e no area above the upper benefit cutoff level is included in the benefit computation The upper benefit cutoff value is also the assumed preventive maintenance treatment failure trigger level for a condition indicator relationship that is assumed to increase over time e g IRI Lower Benefit Cutoff Value The lower benefit cutoff value is the user chosen ower limit to the benefit area computation i e no area below the lower benefit cutoff level is included in the benefit computation The lower benefit cutoff value is also the assumed preventive maintenance treatment failure trigger C 7 level for a condition indicator relationship that is assumed to decrease over time e g friction number Analysis Period The analysis period for a given timing scenario is the earliest age at which one of the individual condition indicator treatment performance re
74. ting do nothing curve is displayed in the chart area on the right side of the dialog box The upper and lower benefit cutoff levels are also plotted as red lines on this same chart To update the chart after making changes to the entered data points click the _ Piet Curve tere Do Nothing Curve Chart As with the first method the regressed do nothing performance relationship is displayed along with the defined benefit cutoff values on the condition indicator chart on the right side of each tab For reference the actual defined lower and upper benefit cutoff values are displayed below the chart To change any details of the displayed regression curve click on the _ Data Points button to re open the Regression Equation Data Entry dialog box In order to compare different regression equation types the R value is displayed on the chart The R value is a statistical characteristic that gives an indication of the goodness of fit of an equation through a particular data set R values range from 0 to 1 0 with an R value of 1 0 indicating a perfect fit i e all data points fall on the regression curve Step 6 Definition of Post Preventive Maintenance Performance Relationships The next step in the setup of the analysis session is to define all of the post preventive maintenance performance relationships associated with the chosen treatment application ages The Treatment Performance Relationship Summary List dialog box displays a li
75. ts include pavement types such as full depth asphalt and HMA overlaid PCC pavements PCC surfaced pavements include C 20 Optimal Timing of Preventive Maintenance Treatments Selection of Condition Indicators x Selection and Definition of Condition Indicators Back After selecting a pavement type select the condition indicators you want to use to define benefit Next set the condition indicator units equation trends curve shapes and lower and upper benefit cutoff values Next Surface Type HMA Surfaced PCC Surfaced HMa amp Surfaced Condition Indicators Lower Benefit Upper Benefit Condition Indicators Units Trend Over Time Cutoff Value Cutoff Value V Composite index 0 to 100 scale Decreasing I Nonload related cracking n o o I Load telated cracking I Oxidation raveling Rutting Avg rut depth it v i g V Roughness smoothness IRI in mi Increasing Friction Friction numbe a meae User Defined Condition Indicators e eat ea A Sy Be D e EE E Ea 3 al Sm a Figure C 5 Selection of Condition Indicators dialog box showing controls associated with an HMA surfaced pavement pavement types such as conventional PCC pavements PCC pavements with PCC overlays and whitetopped HMA pavements The remainder of the controls in this dialog box change to reflect the selected surface type Selection of Condition Indicators The choice of surface type determines w
76. ts the typical performance expected on this type of pavement if no preventive maintenance treatment were applied A performance relationship must be defined on each visible tab before proceeding to the next step The dialog box used to define do nothing performance relationships changes depending on the type of analysis session The interfaces for the Simple and Detailed analysis methods are described separately below Defining Do Nothing Relationships Under the Simple Analysis Method The controls used to define do nothing relationships in a Simple analysis are shown in figure C 9 On this dialog box a separate tab is displayed for each condition indicator included in the analysis session The same controls used to define the do nothing performance relationship are provided on each tab For this Simple analysis method do nothing curves are created by defining three points on the curve a starting point an ending point and a pass through point To facilitate the definition of these three points the expected equation trend i e the user defined trend over time associated with the current condition indicator is displayed in the lower left corner of each condition indicator tab Specific details on defining each of these three points are provided separately below Defining a Starting Point The starting point for a given do nothing curve is defined by entering an expected time zero condition level in the initial condition l
77. user defined composite index Data Entry Method Enter equation directly Composite Index vs Age Fit regression equation through data Equation Coefficient Definition Equation type Linear Coefficients Linear Model 0 to 100 scale Equation Form y m Age b m 2 5 b 100 Equation Details 10 15 y 2 500 x 100 000 Age years Equation Trend Decreasing 2 a Benefit cutoff values Lower 50 Upper 100 Figure C 10 Example of the Definition of Do Nothing Curves dialog box in the Detailed Analysis with the Equation Coefficient Definition area displayed known equation coefficients or fitting a regression equation though entered condition versus age data points Choosing the Enter equation directly data entry method displays the Equation Coefficient Definition area Additional options include choosing an equation type and defining the associated equation coefficients Choosing the Fit regression equation through data choice displays the Regression Equation Details area this then requires the entry of actual performance data points and the selection of the type of model Method 1 Entering Equations Directly The Equation Coefficient Definition area is displayed when the user chooses the Enter equation directly data entry method see figure C 10 Required inputs include the selection of an equation type and definition of associated C 33 equation coefficients More specific details
78. with an Effectiveness Index of 100 that scenario with the largest B C ratio is then highlighted in the output tables Also included as part of the Effectiveness Summary table is the expected life of the pavement resulting from the preventive maintenance treatment application and the associated expected extension of life computed as the difference between the expected age at the end of the treatment life minus the predetermined expected do nothing pavement life KEY CONCEPTS OF THE METHODOLOGY The final analysis methodology used within the analysis tool is built on a number of key concepts that must be understood when setting up and conducting an analysis session This section provides a quick reference summary of these concepts A more detailed explanation of most of these analysis method concepts is presented in chapter 3 of the main report Benefit Benefit is defined as the observed influence usually positive but it could also be negative on any one or more included condition indicators resulting from the application of a preventive maintenance treatment Using this definition there could be many different types of benefit associated with a given application of a preventive maintenance treatment e g applying a chip seal could result in benefits in the form of improved friction retarded oxidation reduced rutting and so on Specifically benefit for a given condition indicator is determined by comparing the area associated with

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