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Interactive Graphics Intersection Design System

1. IGIDS Leg IGIDS Leg enlarged 10 EOT IGIDS Leg Centerline IGIDS Leg Centerline H IGIDS Inbound Lane IGIDS Inbound Lane IGIDS nner Edge Segment IGIDS Inner Edge Segment 11 IGIDS Stop Line Seoment IGIDS Stop Line Segment 12 Id IGIDS Outer Edge Curb Return Segment IGIDS Outer Edge Curb Return Segment 13 IGIDS automatically sorts an alternative s list of legs a leg s list of inbound lanes a leg s list of outbound lanes and each list of segments This automatic sorting allows the user to enter elements in any order An alternative is considered completed when all of its legs are completed A leg is considered completed when all of its centerlines inbound lanes outbound lanes inner edge curb returns and outer edge curb returns are completed A lane is considered completed when all of its inner edges outer edges stop lines inner edge stripings outer edge stripings and stop line stripings are completed A list of segments is considered completed when 1 no segments are entered for optional elements like curb returns and striping 2 one segment is entered or 3 two or more segments are entered and there is no geometric gap between adjacent segments IGIDS maintains the design as descriptive data s
2. TNT TEE 17 Vertical Alignment Based Sight Distance Checking 17 Traffic Control Device Placement 277 Training Vend isa SEES SENE EDR cedido bua apa Ede 27 Highway Capacity Manual Chapter 9 Analysis EG 28 Other FT Lana 29 REFERENCES PET a si 33 APPENDIX ssasssssssssssasa ssseescnesoosusson s osesscssavssesesossoessesasoscevesenseeseveosecesore wevsessessocsoeoveovsun 3 7 CHAPTER 1 INTRODUCTION RESEARCH PROBLEM STATEMENT The recently completed Research Study 0 1308 Interactive Graphics Intersection Design System IGIDS Ref 2 has produced computer aided design software for intersection design redesign and modification At the April 13 1994 presentation of these research results to the Area 3 Committee members requested at least two additional features be provided These features included the following requests 1 supplement the already provided sight distance checks based on horizontal alignment with vertical alignment based sight distance checking and 2 allow the designer to easily place signs pavement markings and signalization layout features into a graphics file that can be plotted from IGIDS or the Texas Department of Transportation TxDOT Automated Plan Preparation System APP and automatically generate a current bill of materials file as traffic control features are placed
3. The IGIDS software has been designed to operate on a variety of hardware platforms including workstations and personal computers The graphics based primary and utility functions provided through the software are therefore technically available to most individuals having computing hardware access However many potential users only fully employ IGIDS if user training is provided Such training should be developed and offered as soon as possible BACKGROUND The research team and the TxDOT Departmental Project Director PD have recently completed the initial version of the Interactive Graphics Intersection Design System IGIDS The IGIDS software has been designed to facilitate extension and expansion Throughout the development process significant effort has been devoted to designing and implementing an intricate foundation for an evolving fully featured IGIDS The system that has evolved operates upon this foundation that is it has been carefully configured to permit the addition of capabilities that will ultimately make the IGIDS an extremely efficient and valuable engineering tool The IGIDS conceptual background is included here for the sake of completeness The previous TxDOT research projects that developed IGIDS at the Center for Transportation Research at The University of Texas at Austin included the following 1 Project 0 1139 Ref 1 conducted from September of 1988 to September of 1991 This project undertook the initial desi
4. Programmer s Guide Research Report 184 2 CFHR 3 18 72 184 2 Center for Highway Research The University of Texas at Austin Austin Texas December 1977 Lee Clyde E Glenn E Grayson Charlie R Copeland Jeff W Miller Thomas W Rioux and Vivek S Savur The TEXAS Model for Intersection Traffic User s Guide Research Report 184 3 CFHR 3 18 72 184 3 Center for Highway Research The University of Texas at Austin Austin Texas July 1977 Rioux Thomas W and Clyde E Lee TEXAS A Microscopic Traffic Simulation Package for Isolated Intersections 56th Annual Meeting of the Transportation Research Board Washington D C January 1977 and Transportation Research Record 644 1977 pages 45 51 Lee Clyde E Robert F Inman and Wylie M Sanders User Friendly TEXAS Model Guide to Data Entry Research Report 361 1F CTR 3 18 84 361 1F Center for Transportation Research The University of Texas at Austin Austin Texas November 1985 Lee Clyde E Randy B Machemehl and Wiley M Sanders TEXAS Model Version 3 0 Diamond Interchanges Research Report 443 1 F Center for Transportation Research The University of Texas at Austin Austin Texas January 1989 Rioux Thomas W Simulation of Diamond Interchange Traffic Operations 70th Annual Meeting of the Transportation Research Board Washington D C January 1991 Rioux Tom Robert Inman Randy B Machemehl and Clyde E Lee Texas Model
5. log box dia Signal ing Data for Pretimed Tim IGIDS 31 IGIDS Timing Data for NEMA Actuated Controller dialog box 32 10 11 12 13 14 REFERENCES Rioux Thomas W Robert F Inman Charles H Berry Clyde E Lee and Randy B Machemehl Interactive Graphics Intersection Design System First Stage Development Research Report 1139 1F Center for Transportation Research The University of Texas at Austin Austin Texas November 1991 Rioux Thomas W Robert F Inman Randy B Machemehl and Clyde E Lee Interactive Graphics Intersection Design User s Manual Research Report 1308 1F Center for Transportation Research The University of Texas at Austin Austin Texas December 1994 Rioux Thomas W Robert F Inman Randy B Machemehl and Clyde E Lee Interactive Graphics Intersection Design System IGIDS Training Manual Research Report Number 0 1291 1 Center for Transportation Research The University of Texas at Austin Austin Texas January 1998 MicroStation Customer Support Library Reference Manual Version 4 for Clix DOS and MAC Document DSYS11540 Bentley Systems Inc and Intergraph Corporation 1990 MicroStation User s Guide Version 4 for Clix Document DGA051410 Bentley Systems Inc and Intergraph Corporation 1991 MicroStation Reference Guide Version 4 for Clix Document DGA051710 Bentley Systems Inc and Intergraph Corporation 1991 MicroStation MDL M
6. Text Intersection Alternative Leg Outer Edge Curb Return Seg Text Intersection Alternative Leg Inbound Lane Inner Edge Seg Text Intersection Alternative Leg Inbound Lane Outer Edge Seg Text Intersection Alternative Leg Inbound Lane Stop Line Seg Text Intersection Alternative Leg Inbound Lane Inner Edge Striping Seg Text Intersection Alternative Leg Inbound Lane Outer Edge Striping Seg Text Intersection Alternative Leg Inbound Lane Stop Line Striping Seg Text Intersection Alternative Leg Inbound Lane Other Striping Seg Text Intersection Alternative Leg Outbound Lane Inner Edge Seg Text Intersection Alternative Leg Outbound Lane Outer Edge Seg Text Intersection Alternative Leg Outbound Lane Stop Line Seg Text Intersection Alternative Leg Outbound Lane Inner Edge Striping Seg Text Intersection Alternative Leg Outbound Lane Outer Edge Striping Seg Text Intersection Alternative Leg Outbound Lane Stop Line Striping Seg Text Intersection Alternative Leg Outbound Lane Other Striping Seg Text IGIDS Object Relationships Stondord 4X4 Stondord 4x4 IGIDS Alternative IGIDS Alternative Slondord 4X4 Slondord 4X4 IGIDS Text on Alternative IGIDS Text on Alternative Stondord 4X4 Standard 4X4 il IGIDS Leg IGIDS Leg
7. VERTICAL ALIGNMENT BASED SIGHT DISTANCE CHECKING IGIDS commands were renamed and added to accommodate vertical alignment based sight distance checking The old IGIDS commands for horizontal sight distance were renamed distance TOOLS gt Sight Dist gt Horizontal Stopped TOOLS gt Sight Dist gt Horizontal Yield TOOLS gt Sight Dist gt Horizontal No Control and TOOLS Sight Dist gt Horizontal Del Graphics The new IGIDS commands for vertical sight distance are 17 TOOLS gt Sight Dist gt Vertical Stopped TOOLS gt Sight Dist gt Vertical Yield TOOLS gt Sight Dist gt Vertical No Control TOOLS gt Sight Dist gt Vertical Del Graphics IGIDS horizontal sight distance calculations are performed for the following scenarios no control stop sign controlled and yield sign controlled lanes Starting with a car in the inbound lane the path that the car would take from its position in the inbound lane to the conflict point within the intersection is drawn then the path that the car on the conflicting leg would take from its position on the conflicting leg to the conflict point within the intersection is drawn finally a line is drawn from the driver s eye position within the car in the inbound lane to the front bumper position of the car on the conflicting leg The distance from the conflict point within the intersection to the front bumper position of the car on the inbound lane and to the car on the conflicting leg is calculated based o
8. Heads m Pavement Markings Striping m Traffic Control Features Bill of Materials a Types of Striping solid line broken line dotted line lane drop no passing inbound no passing outbound double solid line and double broken line Width 4 6 8 12 18 and 24 inches 100 150 200 300 450 and 600 mm Color while and yellow ment Markings of Materials ular Report Interactive Graphics Intersection Design System Version 03 00 Current Date and Time 34 Jan 1988 14 06 47 ersectian Description Interactive Graphics Intersection Design System Alternative Description c ligidalsys detalSTO SXs DAT ternative Number 1 istriping Solid Line 150 am white 1950 17 38 Striping Broken Line 150 am white 2826 08 M Striping Double Solid Line 150 mm yeiiow 375 36 3 4 Striping Solid Line 450 ma white 43 20 x Signal 3 lens vertical 8 Signal 3 lens protected left vertical Channelixataon Left Controligr Pretimed size 1 Chanvelization Right Chanoelisation Straight DS External Analysis Tools IRIS i IGIDS builds input to external analysis fool for execution outside IGIDS and may retrieve output results for processing within IGIDS m Texas Model for Intersection Traffic m Signal Operations Analysis Package m TxDOT Automated Plan Preparation System iffic Control Features RENE Tabular Report s Spreadsheet Importable File preadsheet Importable Fil
9. in a classroom mode The IGIDS Training Manual consists of three major parts The first part contains an approximate 14 page Overview of IGIDS that reviews IGIDS concepts and terminology The second part contains an Introduction to MicroStation 95 that reviews the pertinent MicroStation 95 commands necessary to operate IGIDS and includes a simple MicroStation exercise The third part contains ten exercises that starting with a simple example and going on to greater complexity utilize most functions within IGIDS Each exercise is scripted in detail so the 27 student knows exactly what is expected For the student that gains experience quickly the key commands and user entries are emphasized in bold type The Overview should be read prior to a formal class The Introduction to MicroStation 95 and the Simple Example must be completed first in order because other exercises use files developed through these exercises The training should take approximately two 8 hour days Numerous screen captures are incorporated and a plot of the final form is provided HIGHWAY CAPACITY MANUAL CHAPTER 9 ANALYSIS At the request of the TxDOT Project Director the IGIDS Highway Capacity Manual HCM Chapter 9 Analysis was updated to the procedures defined by the 7994 Highway Capacity Manual Special Report 209 Ref 30 In addition to updating the procedures a dialog box was developed for HCM Chapter 9 Analysis which allows the user to sele
10. provide plotting capabilities but relies upon the graphics engine to perform such operations IGIDS accommodates up to fifteen alternative designs for an intersection Existing intersection conditions will normally constitute one alternative Each alternative and its major graphical component groupings is placed on separate graphical levels or planes so that it can be displayed independently or not displayed in a particular view by the graphics engine IGIDS allocates a user graphical level or plane and allocates a scratch graphical level or plane All or part of an intersection alternative can be copied to another alternative and all or part of an intersection alternative can be modified by IGIDS commands In addition any number of reference files may be attached to the master design file by the graphics engine IGIDS can locate elements in these reference files to be added as graphics for IGIDS Finally the graphics engine may display a raster image a scanned photograph or other raster data IGIDS graphics will normally be two dimensional in plan view and will use a state plane coordinate system operating in either English or metric units Coordinates distances and other real numeric data are stored as 16 significant digit 64 bit double precision floating point variables in the master units of the graphics engine feet or meters All angular data will be stored as the same type variables but in degrees All counter or indexing
11. work in English units or in metric SD units After a project is started in IGIDS the units cannot be changed During startup IGIDS tests the MicroStation master unit character description for the design file If the first character of the description is f or F and the second character of the description is t or T then English units are used If the first character of the description is m or M and the second character of the description is blank or null then metric units are used If the units cannot be determined an IGIDS Units Definition dialog box is displayed so the user can choose English or metric units After a choice is made a warning message is displayed to the user to Please make sure design file master units are set to feet or Please make sure design file master units are set to meters IGIDS Units Definition dialog box All calculations within IGIDS were evaluated to determine whether English units were involved Where appropriate the equivalent metric design value was given as an alternative In other cases the English unit value was converted to metric Some dialog boxes include both English units and metric units in the name such as a vehicle type for vehicle turn templates WB 60 18 means WB 60 in English units and WB 18 in metric units and a width for striping 6 150 means 6 inches or 150 millimeters This version of IGIDS was made available to TxDOT when the metrication process was completed
12. would allow the user to easily change the elevation information without changing the 2 D plan coordinates The station elevation grade and cross slope values are saved with each leg s data The sight line spacing is the 2 D distance between points along the conflicting path from the object s initial position to the stop line While a large value will produce fewer vertical sight lines and consequently take less computation time it may miss some small objects in the terrain on the other hand a small value will produce a larger number of vertical sight lines and take more computation time but may find smaller objects in the terrain Moreover the user may input the driver s eye height and the object height Additionally the traffic control cabinet sometimes represents a significant sight obstruction accordingly the user may enter the elevation of the top of the traffic control cabinet The sides of the traffic control cabinet are extended to the terrain so that a driver s view is blocked under the traffic control cabinet The elevation of the top of the traffic control cabinet is saved with the alternative s data while the sight line spacing driver eye height object height and viewing options are saved with the intersection s data IGIDS initially uses default values for station elevation grade cross slope elevation of the top of the traffic control cabinet sight line spacing driver eye height object height and viewing options IGI
13. ACEMENT IGIDS commands were added to accommodate striping and traffic inventory reporting The new IGIDS command for striping is TOOLS gt Traffic gt Striping and the new IGIDS commands for traffic inventory reporting are TOOLS gt Traffic gt Inventory gt Report and TOOLS gt Traffic gt Inventory gt Spreadsheet The following IGIDS menus show the striping and traffic inventory reporting commands 22 IGIDS Striping and Traffic Inventory Reporting Command Menus IGIDS provides for the placement and bill of materials for the following traffic control devices yield sign stop sign 3 lens signal head 3 lens protected left signal head left turn channelization arrow straight movement channelization arrow right turn channelization arrow U turn channelization arrow pretimed controller NEMA controller solid line striping broken line striping dotted line striping lane drop striping no passing inbound striping no passing outbound striping double solid line striping and double broken line striping IGIDS adds graphics to the database and to the graphics file for each type of traffic control device The graphics are stored on the level for traffic control and thus may be displayed or not displayed using the IGIDS VIEW gt TRAF CONTROL gt CURRENT ON and VIEW gt TRAF CONTROL gt CURRENT OFF commands IGIDS provides for the placement modification and deletion of striping using the following IGIDS Striping dialog box 23 3 Str
14. AK Corporation North Miami Beach Florida 1996 McTrans Newsletter Center for Microcomputers in Transportation Transportation Research Center University of Florida Gainesville Florida 1997 35 36 APPENDIX The following pages contain prints of the Microsoft PowerPoint slides delivered with the IGIDS Training Manual 37 eractive Graphics Intersection Design System IGIDS Thomas W Rioux Robert F Inman Randy B Machemehl Clyde E Lee The University of Texas at Austin Center for Transportation Research CTR and Texas Department of Transportation TxDOT Assists engineers in the analysis and design of isolated at grade intersections m Operates on personal computers and workstations with MicroStation m Provides the Intersection Design Engineer with suitable tools to assist with each intersection design stage u MicroStation used as a graphics engine to perform all graphics input and output m Standard intersection layouts library that can be drawn and modified m Intersection geometry defined by existing MicroStation graphics m Intersection geometry defined by user key in of data POT IGIDS Research Project 0 1139 9 88 to 9 91 initial design and development using MicroStation Clix V4 m Project 0 1308 9 91 to 9 93 additional features using MicroStation Clix V4 m Project 0 1308 9 93 to 9 94 extension conversion to MicroStation DOS V4 MDL m Project 0 1291 9 95 to 9 97 metr
15. DISCLAIMERS The contents of this report reflect the views of the authors who are responsible for the facts and the accuracy of the data presented herein The contents do not necessarily reflect the official views or policies of the Federal Highway Administration or the Texas Department of Transportation This report does not constitute a standard specification or regulation There was no invention or discovery conceived or first actually reduced to practice in the course of or under this contract including any art method process machine manufacture design or composition of matter or any new and useful improvement thereof or any variety of plant which is or may be patentable under the patent laws of the United States of America or any foreign country NOT INTENDED FOR CONSTRUCTION BIDDING OR PERMIT PURPOSES Randy B Machemehl P E Texas No 41921 Research Supervisor iv TABLE OF CONTENTS CHAPTER 1 INTRODUCTION 1 Research Problem Statement PEE 1 Background i oett naqa u ug EEG 1 Caution RN A DAV RT E Ke SE EE i Ohjechzyeee nisani reas J TT EG lo Implementation aaa 6 Benefits ue cesa Tee aaepe s Tea ve Ese ed usa EMC 6 CHAPTER 2 IGIDS NN LT Metrication
16. DS Vertical Sight Distance Dialog Box 19 The other major consideration for vertical sight distance calculations was the representation of the ground terrain and other elevation features Virtually all Digital Terrain Model DTM programs including GEOPAK Ref 32 have the capability to produce a triangle file that represents the 3 D terrain This triangle file is a 3 D file containing 3 D triangles where the x y and z coordinate of each vertice of the triangle is specified The ground terrain and other elevation features such as buildings may be represented by the DTM It is up to the user to create the triangle file with their DTM package to represent all terrain and man made features that may restrict vertical sight distance The triangle file must have all triangles to be used by IGIDS on a single level with any color style and weight It is mandatory that the master units of the triangle file match the value of the IGIDS file It is desirable but not mandatory that the subunits and positional units of the triangle file match the values of the IGIDS file The triangle file may not be rotated in relation to the IGIDS file The user may attach the triangle file as a reference file to the IGIDS file however the IGIDS file must be a 3 D file to accommodate the reference attachment Because all other components of IGIDS do not care if the design file is 2 D or 3 D the user may begin using IGIDS in a 2 D file When vertical sight distance calcul
17. Model for Intersection Traffic TEXAS Model Refs 16 23 the Signal Operations Analysis Package SOAP Refs 24 26 and the TxDOT Automated Plan Preparation System are supported by IGIDS The TEXAS Model provides microscopic simulation of vehicular traffic flow through a single intersection or a diamond interchange and generates both a statistical summary and animated graphics that show drawn to scale color coded vehicle types moving through the intersection geometry Selected TEXAS Model statistics may be displayed in bar chart format for each leg and for all intersection legs SOAP develops and assesses isolated intersection signal timing plans Data for both the built in and external analyses are drawn from a common database maintained by IGIDS Many of these data are extracted from the graphical intersection geometry defined by the user Some nongraphical data such as traffic volumes must be keyed in IGIDS is a MicroStation MDL application MicroStation is a computer aided drafting CAD software package developed by Bentley Systems Inc and is the CAD standard currently implemented by the Texas Department of Transportation TxDOT The user must have a working version of MicroStation to run IGIDS IGIDS is available for MicroStation Version 4 0 for DOS Windows and Clix for MicroStation Version 5 for DOS Windows Windows 95 Windows NT and Clix and for MicroStation 95 for DOS Windows and Windows 95 Windows NT IGIDS data may be in English
18. S Stop Line Segment IDS Outer Edge Curb Return En DS Internal Analysis Tools Horizontal sight distance checking for stop yield and uncontrolled conditions m Vertical sight distance checking within the horizon al sight triangle m Highway Capacity Manual Chapter 9 analysis for signalized intersections u Bill of Materials for traffic control features prizontal Sight Distance Checking Load IGIDS object data from a library of standard intersection layouts m Load IGIDS object data from an IGIDS database of previously saved IGIDS object data m Save IGIDS object data to an IGIDS database rtical Sight Distance Checking Dependent on Terrain Roadway Alignment Access Digital Terrain Model DTM by identifying a single triangle from DTM triangle reference file m Horizontal alignment defined by selection of IGIDS legs lanes m Vertical alignment defined by station elevation grade and cross slope rtical Sight Distance Checking tical Sight Distance ecking Yield Sign Control tical Sight Distance hecking No Control iffic Signal Timing tetimed Signal Controllers affic Turn Movement Counts affic Signal Timing hway Capacity Manual MA Signal Controllers Zhapter 9 Stopped Delay Stopped Delay ghway Capacity Manual Signals and Pavement apter 9 V C Ratio rkings V C Ratio Stop and Yield Signals Pretimed and NEMA Controllers Traffic Signal
19. Technical Report Documentation Page 2 Government Accession No 3 Recipient s Catalog No 5 Report Date January 1998 6 Performing Organization Code 8 Performing Organization Report No Research Report 1291 2 10 Work Unit No TRAIS 11 Contract or Grant No 0 1291 12 Sponsoring Agency Name and Address 13 Type of Report and Period Covered Texas Department of Transportation Research Report 9 96 8 97 Construction Research Section P O Box 5080 14 Sponsoring Agency Code Austin TX 78763 5080 15 Supplementary Notes Project conducted in cooperation with the Federal Highway Administration 16 Abstract 1 Report No FHW A TX 98 1291 2 4 Title and Subtitle INTERACTIVE GRAPHICS INTERSECTION DESIGN SYSTEM IGIDS RESEARCH REPORT 7 Author s Thomas W Rioux Robert Inman Randy B Machemehl and Clyde E Lee 9 Performing Organization Name and Address Center for Transportation Research The University of Texas at Austin 3208 Red River Suite 200 Austin TX 78705 2650 The Interactive Graphics Intersection Design System IGIDS a software package that operates on personal computers and workstations has been developed to assist engineers in the analysis and design of isolated at grade intersections In addition to documenting the development of this program this report describes the new features incorporated into the IGIDS package 17 Key Wo
20. anual Version 4 for DOS Document DGA022410 Bentley Systems Inc and Intergraph Corporation 1991 MicroStation User s Guide Version 5 Document DGA0514110 Bentley Systems Inc and Intergraph Corporation September 1993 MicroStation Reference Guide Version 5 Document DGA054210 Bentley Systems Inc and Intergraph Corporation September 1993 MicroStation Development and Support Guide Version 5 Document DGA054310 Bentley Systems Inc and Intergraph Corporation September 1993 MicroStation MDL Programmer s Guide Version 5 Document DGA055010 Bentley Systems Inc and Intergraph Corporation November 1993 MicroStation MDL Function Reference Manual Version 5 Document DGA055110 Bentley Systems Inc and Intergraph Corporation December 1993 MicroStation 95 Academic Suite PC Setup Guide Bentley Systems Inc 1995 MicroStation 95 Academic Suite Upgrade Guide Bentley Systems Inc 1996 33 15 16 17 18 19 20 21 22 23 25 MicroStation 95 Academic Suite User s Guide Bentley Systems Inc 1995 Lee Clyde E Thomas W Rioux and Charlie R Copeland The TEXAS Model for Intersection Traffic Development Research Report 184 1 CFHR 3 18 72 184 1 Center for Highway Research The University of Texas at Austin Austin Texas December 1977 Lee Clyde E Thomas W Rioux Vivek S Savur and Charlie R Copeland The TEXAS Model for Intersection Traffic
21. ations are needed the user can save IGIDS to a database exit IGIDS open a 3 D MicroStation 95 design file start IGIDS and load the previously saved IGIDS database without any loss of data The traffic control cabinet is represented by 12 triangles and is checked in addition to the terrain triangles whether the traffic control cabinet is displayed in 3 D or not To perform the vertical sight distance checks a 3 D line is drawn from the driver s eye position using the driver s leg s station elevation grade cross slope and driver eye height to the object s position using the object s leg s station elevation grade cross slope and object height The 3 D line is checked against all triangles terrain and the traffic control cabinet to determine the position closest to the driver s eye position where the 3 D line goes under the terrain traversing from the driver s eye position to the object s position and the position closest the object s position where the 3 D line goes under the terrain traversing from the object s position to the driver s eye position If the 3 D line does go under the terrain it is considered an obstructed line otherwise it is considered an unobstructed line The obstructed lines may have a color that differs from the unobstructed lines In addition the portion of the obstructed line from the driver s eye position to the position closest the driver s eye position where the 3 D line goes under the terrain is referred to as th
22. bjects are added to the list so that the user can enter geometry data items in any order IGIDS automatically sets the direction of any entered graphical IGIDS object so that it will conform to the sorted direction of the list of which it is a part Hierarchical geometry refers to the fact that the IGIDS objects are related in a parent child relationship Each IGIDS object will comprise only one parent IGIDS object and may have zero or more children IGIDS objects An IGIDS object can have different parent IGIDS object types with the type of parent being associated with the attributes of an IGIDS object Each IGIDS object knows the type of its parent IGIDS object and which specific IGIDS object entry is its parent An IGIDS object can have more than one category of child IGIDS object The number of children IGIDS objects accommodated by IGIDS is virtually infinite Each parent IGIDS object maintains the current number of children IGIDS objects and has a pointer to the beginning and ending children IGIDS objects for each category of children IGIDS objects Each IGIDS object has a pointer to the previous and to the next IGIDS object on the list An IGIDS object with a null previous pointer is the first IGIDS object on the list An IGIDS object with a null next pointer is the last IGIDS object on the list An IGIDS object with a null previous pointer and a null next pointer is the only IGIDS object on the list Most high level IGIDS objects serve to group the
23. children IGIDS objects and only the lowest level IGIDS objects have a graphical representation Any procedure applied to an IGIDS object is automatically applied to all the children of the IGIDS object The six IGIDS objects are Intersection Alternative Leg Lane Seg Segment and Text There is only one intersection IGIDS object and it has a list of up to fifteen alternatives and other intersection data Each alternative IGIDS object has an intersection parent pointer a list of legs a list of text and other alternative data Each leg IGIDS object has an alternative parent pointer a list of centerline segments a list of inbound lanes a list of outbound lanes a list of inner edge curb return segments a list of outer edge curb return segments and other leg data Each lane IGIDS object has a leg parent pointer a list of inner edge segments a list of outer edge segments a list of stop line segments a list of inner edge striping segments a list of outer edge striping segments a list of stop line striping segments a list of other striping segments and other lane data Each segment IGIDS object has a leg lane parent pointer a list of texts and data for either an arc of a circle or a line Each text IGIDS object has an alternative segment parent pointer and text data Each IGIDS object may have either a parent or child relationship with other different type IGIDS objects Any IGIDS object may have only one parent but a parent may have none
24. ct numerous options a Peak Hour Factor option was also added to the turn movement count dialog box The SOAP capacity calculations were also adapted to use the new HCM procedures IGIDS Highway Capacity Manual Chapter 9 dialog box 28 IGIDS Traffic Turn Movement Count Peak Hour Factor dialog box OTHER FEATURES A standard MicroStation 95 file name entry dialog box is now used each place where the user was prompted to enter a file name for reading or writing This gives the user the ability to browse the computer system to locate the device directory and file name to be used An example is SAVE TO gt Data Base command 29 GIDS Database File lt ci E igids source sys data IGIDS Database File dialog box Because traffic controller timing data entry was complicated and time consuming a dialog box was developed for the pretimed and NEMA traffic controllers Phases can be added resequenced and deleted timing values can also be applied to all phases or to a single phase For the pretimed controller phase lengths are automatically calculated For the NEMA traffic controller the single ring or dual ring mode of operation may be selected controller options can also be specified for all phases or a single phase The dual entry phase option is selectable when in dual ring mode of operation and dimmed when in single ring mode of operation 30 H T E gU T fr E 3 E o u E g ai en El
25. cts tr m IGIDS uses MicroStation to perform all interactive graphics operations to maintain the graphics engine database and to perform all plotting functions m GIDS software operates above and drives the graphics engine through a higher level language interface m GIDS allows the user to switch easily between executing IGIDS commands and graphics engine commands IGIDS units are automatically determined by design file master units specifications Once a project has been started in a given system of units the system of units may not be changed m 2D or 3D design file 2D for virtually all functions 3D for vertical sight distance checking Easy fo convert between 2D and 3D DS Hierarchical Objects Intersection list of alternatives and intersection data m Alternative maximum of 15 list of legs list of text and alternative data IDS Alternative DS Text on Alternative list of centerline segments inbound lanes outbound lanes inner edge curb return segments and outer edge curb return segments and leg data DS Hierarchical Objects list of inner edge segments outer edge segments stop line segments inner edge striping segments outer edge striping segments stop line striping segments and other striping segments and lane data IDS Hierarchical Objects htinued I Segment arc or line list of text and segment data DS Lane Outer Edge Segment D
26. e nteractive Graphics Intersection Design System Version 03 00 rent Date and Time 14 Jen 1998 14 08 09 tersection Description Interactive Graphics Intersection Design System terzative Dascr pt an criigideieys date 5TD 525 007 ternative Number 3 tripiag Solid Line 150 mm white 1990 17 M riping Broken Line 1S0 am white 2926 08 s iriping Double Solid Line 150 mm yellow 975 364 H Striping Solid Line 45G cm white 43 20 H Signal 3 leas vertical a Signal 3 lans protected left vertical 4 Chaanelization Left 4 Controller Pretimed sise 17 53 PChaunelization Right 4 Channeliration Straight 4 ining Materials IGIDS Training Manual Beginners and advanced exercises Self Paced Printed and World Wide Web formats m Microsoft PowerPoint presentation ftp ftp ce utexas edu fip igids or ftp ce utexas edu igids documentation most but not all chapters dos ustn40 dos ustn50 dos ustn95 winnt ustn50 winnt ustn95 m McTrans in the future Questions
27. e line before obstruction the portion of the obstructed line from the position closest the driver s eye position where the 3 D line goes under the terrain to the position closest the object s position where the 3 D line goes under the terrain is referred to as the line through obstruction and the portion of the obstructed line from the position closest the object s position where the 3 D line goes under the terrain to the object s position is referred to as the line behind obstruction No attempt is made to determine whether the line through the Obstruction is visible at any time between its beginning and ending point The line before obstruction the line through obstruction and the line behind obstruction may each have a 20 different color and may or may not be displayed The traffic control cabinet may also have a different color and may or may not be displayed The position of the object is moved from its initial position toward the stop line for the lane by an amount specified by the user as Sight Line Spacing and the checking process is performed again The procedure ends when the position of the object is beyond the stop line for its lane Below are examples of vertical sight distance calculations for yield sign controlled no control and stop sign controlled situations IGIDS Vertical Sight Distance No Control Calculations 21 IGIDS Vertical Sight Distance Stop Sign Control Calculations TRAFFIC CONTROL DEVICE PL
28. e as scratch graphics IGIDS can then inspect these scratch graphics and add the desired feature to the design Graphics on an existing drawing may be processed in a similar manner Intersection analysis and design software packages will be executed when the user selects from a menu the software package IGIDS will check its database for the appropriate data and prompt the user for any missing data IGIDS will then extract data from the IGIDS database and build the required input files for the software package that was selected The software package will be executed by the operating system as an external or background process and the user may use graphics engine commands to review the output When appropriate the software package output will be displayed by IGIDS CAUTION IGIDS takes control of the active graphics file and deletes everything except what is recognized as scratch graphics all graphics on levels 3 through 62 are controlled by IGIDS while level 2 is the scratch level IGIDS presents to the user an Alert Box Pressing the OK push button will allow IGIDS to continue whereas pressing the Cancel push button will cause IGIDS to exit without deleting any data IGIDS recreates graphics using IGIDS data rather than relying on stored graphics files Therefore at start up any graphics stored in the active file will be deleted The IGIDS design is created by user interaction or by the importation of a previously created design that i
29. e user as graphics displayed by the graphics engine The ID of each IGIDS object that is displayed segs and text is a part of the graphics engine s data and is used to link the graphics engine database with the IGIDS database Each IGIDS graphical item in the graphics engine database will contain the ID of the corresponding item in the appropriate IGIDS structure where the attribute data will be stored The type of the graphics engine element arc line or text will be used to determine the item type segment or text and therefore relate it to the appropriate IGIDS structure The ID will identify the entry number the instance number or the row number in the appropriate IGIDS structure Given an ID IGIDS can search the graphics engine database or access the appropriate IGIDS structure for the specified item The higher level grouping objects may not have a graphical representation During the design process the user may interact with IGIDS to modify the design as desired This interaction is through the graphics engine s user interface The user may 14 identify existing graphical elements specify geometric points and key in alphanumeric data all in response to IGIDS prompts All usual graphics engine functions are always available Graphics engine and IGIDS functions may be used in any desired sequence If there is a need to construct a feature that is beyond IGIDS s capability the graphics engine s tools may be used to create the featur
30. eparation and revision of plans and specifications As computer aided design and drafting tools are upgraded and extended to deal with both routine and complex design tasks engineering talent can be applied to optimizing designs rather than to the more time consuming computing and drafting tasks Although many aspects of highway design are currently handled by RDS much of the detailed effort required for analyzing designing and modifying at grade intersections is not included The technology that has been developed through the evolution of RDS particularly that associated with interactive graphics is now available for application in the design and modification of at grade intersections Intersection design involves not only the geometric structural and drainage features of the roadway that are now handled by RDS but also the many traffic operational aspects Before a set of plans can be finalized detailed analyses must be made concerning capacity level of service delay channelization type of traffic control devices physical siting of traffic control devices safe approach speeds emissions fuel consumption and other factors While various computer aids designed to assist in evaluating these factors have already been developed others are still needed These aids need to be consolidated into a package that can allow easy access by an engineer through a desktop interactive graphics workstation The capability of the desktop workstation
31. for Intersection Traffic Additional Features Research Report 1258 1F CTR 3 18 91 2 1258 1F Center for Transportation Research The University of Texas at Austin Austin Texas January 1993 SOAP84 User s Manual FHW A IP 85 7 Federal Highway Administration U S Department of Transportation January 1985 SOAP84 Data Input Manual FHW A IP 85 8 Federal Highway Administration U S Department of Transportation January 1985 26 27 28 29 30 31 32 33 Supplement to SOAP84 User s Manual FHWA IP 85 7 Transportation Research Center University of Florida Gainesville Florida September 1988 A Policy on Geometric Design of Highways and Streets 1990 American Association of State Highway and Transportation Officials AASHTO 1990 A Policy on Geometric Design of Highways and Streets 1994 American Association of State Highway and Transportation Officials AASHTO 1994 Metric Texas Manual on Uniform Traffic Control Devices for Streets and Highways Texas State Department of Transportation Austin Texas 1980 with Revision 6 1996 Highway Capacity Manual Special Report 209 Transportation Research Board National Research Council Washington D C Third Edition 1994 Vehicle Turning Characteristics For Use In Geometric Design Geometric Design Section Highway Design Division State Department of Highways and Public Transportation Austin Texas 1987 GEOPAK GEOP
32. gn and development of IGIDS using MicroStation Clix Version 4 Refs 4 6 Unix only and the C programming language 2 Project 0 1308 Ref 2 conducted from September 1991 to September 1993 This effort incorporated additional features using MicroStation Clix Version 4 Refs 4 6 Unix only and the C programming language 3 Project 0 1308 extension Ref 2 conducted from September 1993 to September 1994 This project converted IGIDS to MicroStation DOS Version 4 Refs 4 6 using the MicroStation Development Language MDL programming language Ref 7 4 Current Project 0 1291 Ref 3 conducted from September of 1995 to September of 1997 This project added vertical sight distance checking striping and traffic inventory reporting It also developed training material using MicroStation 5 Refs 8 10 and MicroStation 95 Refs 13 15 and the MicroStation Development Language MDL programming language Refs 11 12 Over the past two decades a number of computer aided engineering and design tools such as the Roadway Design System RDS have been developed to handle an ever increasing share of the computational and graphical work required for highway design Such tools offer the potential for significant improvement in engineering efficiency and effectiveness Among other things these aids relieve engineers of the burden of computing coordinate geometry permit visual imaging of proposed geometry and aid significantly in the timely pr
33. has now reached a level such that many intersection analysis and design tasks can be performed quite efficiently by engineers equipped with appropriate software and relatively inexpensive computer hardware Communications technology is also available to permit reliable low cost transfer of design files from micro to micro and to mainframe computers when design tasks dictate the need for more extensive computing power It is also feasible to develop computer software that permits imteractive graphical presentation of all important aspects of at grade intersection design on a variety of computer hardware configurations Interchangeability of software components and design files among these hardware systems will provide a very flexible and efficient working environment for engineers involved in intersection design and modification Intersection design is a complex process that involves many different skills Elements of transportation planning traffic engineering and geometric design contribute to the process of designing the most practicable facility for handling intersection traffic Traditionally the design engineer has relied on the application of manual or sometimes computer aided procedures to determine the most appropriate alternative that satisfies the objectives The process involves geometric layout traffic analysis channelization selection and placement of traffic control devices timing of traffic signals lighting drainage fuel consum
34. ication vertical sight distance striping traffic control bill of materials and develop training 2 m Built in Analysis Tools m Data Manipulation Tools DS Drawing Tools Intersection geometry defined by Texas Model for Intersection Traffic data files Intersection defined by loading a previously saved IGIDS database m Traffic signs signals and striping placed by the user IDS Manipulation Tools Add copy delete rotate and modify intersection geometric components Enter and modify traffic data m Enter and modify traffic controller phasing and timing m Add remove and modify curb returns DS Built in Analysis Tools tinued Procedures of the 1994 Highway Capacity Manual Chapter 9 Signalized intersections may be used to find v c ratios and delays for intersections with pretimed controllers m An inventory or bill of materials for traffic control features can be requesied in printed or spreadsheet compatible input file format TOP PUT OT Use MicroStation as a CAD Engine Use Relational Hierarchical Geometry IGIDS Object Data stored using double precision floating point numbers m Save and load IGIDS object data m Create graphics from IGIDS object data m Develop internal Analysis Tools m Interface to External Analysis Tools IDS Built in Analysis Tools Vehicle turning templates for the standard AASHTO vehicles Horizontal sight distance checking sfop sign controlled yield s
35. ign controlled uncontrolled m Vertical sight obstruction checking within the horizontal sight distance triangle using a Digital Terrain Model DTM triangle file IDS Data Manipulation Tools GIDS prepares data files for analyses hat are executed outside IGIDS and en brings the results back into IGIDS TEXAS Model for intersection Traffic TEXAS Signal Operations Analysis Package SOAP TXDOT Automated Plan Preparation Sysiem APP icroStation as a CAD Standard Bentley Systems Inc a MicroStation is the CAD standard currently implemented by the Texas Department of Transportation TxDOT m MicroStation is used by virtually every State DOT in the United States roStation as a CAD Standard tinued I MicroStation is used world wide Many operating systems and hardware platforms are supported m Provides drawing and plotting tools m Provides dialog box interface m User can switch between IGIDS commands and MicroStation commands m DOS Windows MicroStation Versions 4 5 and 95 m Windows 95 and Windows NT MicroStation Versions 5 and 95 g Clix MicroStation Versions 4 and 5 lational Hierarchical Geometry u Relational the single absolute coordinate is the center of the intersection all geometric definitions are relative to parent object m Hierarchical the parent child relationships are maintained by IGIDS all commands are automatically processed by IGIDS for child obje
36. iping IGIDS Striping Dialog Box The Type of Striping may be 1 solid line 2 broken line 3 dotted line 4 lane drop 5 no passing inbound 6 no passing outbound 7 double solid line or 8 double broken line The Width in mm may be 1 4 100 2 6 150 3 8 200 4 12 300 5 18 450 or 6 24 600 The Color may be 1 White or 2 Yellow The Shift is a value in decimal master units that defines the distance from the start of the reference object to the start of the solid portion of the stripe in the longitudinal direction This does not affect the length of the solid portion of the stripe but offers an offset for the start of the pattern The Reference Object Type may be 1 IGIDS Seg a single IGIDS segment 2 IGIDS Edge all IGIDS segments making up an edge such as leg centerline leg inner edge median curb return leg outer edge curb curb return lane inner edge lane outer edge or lane stop line or 3 scratch seg any graphics drawn by MicroStation on the scratch level The Mode may be 1 Place 2 Modify Attributes or 3 Delete When in Place Mode the Type of Striping Width in mm Color Shift and the Reference Object Type may be specified Selecting and confirming a Reference Object Type will cause IGIDS to 1 prompt for the trim length from the start of the reference object the default will be 0 which means to start at the beginning of the reference object 2 prompt for the stripe length the defa
37. line style definitions The following table summarizes the custom line styles developed Stripe Type Metric double broken line Metric double broken line dotted line dotted line dotted line Metric double solid line Metric double solid line DSL E6 English 6inches DSL M150 Metric _ lane drop lane drop no passing inbound no passing inbound no passing outbound NPO M100 Metric no passing outbound Metric IGIDS Striping Custom Line Styles 25 For inventory purposes the number of signs signal heads channelization arrows and controllers is determined while the linear meters or feet of striping of a certain type width and color are calculated The traffic inventory may be a report suitable for printing or a spreadsheet compatible input file that may be imported into most popular spreadsheet programs e g Microsoft Excel The following example of striping and traffic control graphics show a traffic inventory report and the traffic inventory spreadsheet generated for the design IGIDS Striping and Traffic Control Graphics 26 Interactive Graphics Intersection Design System Version 03 00 Current Date and Time 14 Jan 1998 14 06 47 Intersection Description Interactive Graphics Intersection Design System Alternative Description c igids sys_data STD_5X5 DAT l H H M Alternative Number 1 Striping Solid Line 150mm white 1990 17 M Striping Broken Line 150mm white 2926 08 M Stri
38. n the speeds specified and procedures in A Policy on Geometric Design of Highways and Streets 1990 Ref 27 and in A Policy on Geometric Design of Highways and Streets 1994 Ref 28 The vertical sight distance calculations use the same procedures to determine the 2 D horizontal sight triangle and to then check for sight obstructions within the 2 D horizontal sight triangle from the driver s 3 D eye position to the object s 3 D position as the object moves toward the stop line of the conflicting path The following IGIDS menu shows the sight distance commands IGIDS Sight Distance Command Menu 18 a a The IGIDS was originally designed using 2 D The coordinates of a point were represented by the x and y coordinates of the point To implement vertical sight distance checking the elevation of a point needs to be input or calculated The goal was to minimize the input required from the user while providing a reasonably accurate definition for elevation Since the intersection of two paths in the intersection is at a single point the elevation of that single point would be the same The legs of an intersection are generally planar near the intersection such that a single elevation point somewhere on the leg centerline plus the grade information could specify the longitudinal elevation while the cross slope could define the transverse elevation of the points along a leg This technique would allow each leg to have independent grade information and
39. one or more children Only Segs and Text have displayable graphic elements All others have graphical visibility owing solely to the attached child IGIDS objects Each IGIDS object may have a virtually unlimited number of children The one exception to this is the number of Alternatives is limited to fifteen There is always only one Intersection The leg centerline must be entered and completed before any lanes may be attached An IGIDS command applied to an IGIDS object is automatically applied by IGIDS to all child IGIDS objects of the selected IGIDS object It is convenient to subclassify some IGIDS object types The IGIDS object type Text is seen to have more than one possible type of parent When each Text is created it will be subclassified to be either Text on a Seg or Text on an Alternative This designation will remain unchanged for the life of the Text Both Lane and Seg are seen also to have subclassifications A Lane is either an Inbound Lane or an Outbound Lane A Seg is a Lane Inner Edge Seg Lane Outer Edge Seg Lane Stop Line Seg Lane Inner Edge Striping Seg Lane Outer Edge Striping Seg Lane Stop Line Striping Seg Lane Other Striping Seg Leg Centerline Seg Curb Return Inner Edge Seg or Curb Return Outer Edge Seg Note also that Segs may have either Lane or Leg parents Intersection Alternative Text Intersection Alternative Leg Centerline Seg Text Intersection Alternative Leg Inner Edge Curb Return Seg
40. or IGIDS user training course s IMPLEMENTATION Results of this project can be put into immediate use by the Texas Department of Transportation TxDOT personnel who perform intersection design and improvement tasks The IGIDS may be utilized by both division and district personnel of the Department as well as by engineers in other governmental agencies Although the IGIDS is not a substitute for sound engineering analysis and judgment it provides engineers with powerful computational and graphical tools that can be used to develop and evaluate feasible alternative solutions to intersection traffic problems and thereby make sound engineering decisions BENEFITS Effectiveness and efficiency of intersection geometry traffic control signage and channelization are of growing importance to all traffic engineering agencies within the state of Texas User costs such as delay and fuel consumption and auto emissions are directly related to intersection operations The additional IGIDS features developed in this research project can help ensure appropriateness and efficiency of intersection design and improvement programs The IGIDS training resources resulting from the research will help potential users of the software learn of its capabilities and how to best employ IGIDS features 16 CHAPTER 2 IGIDS DEVELOPMENT METRICATION The first task undertaken in the IGIDS development was the metrication of IGIDS It was decided that IGIDS should
41. or metric units though once a project has been started in a given measurement system the system of units may not be changed While IGIDS may be operated using a 2 D MicroStation design file a 3 D file is required for vertical sight obstruction checking within the horizontal sight distance triangle To change the file format from 2D to 3D the user may save the IGIDS project to a database file enter a 3D file and then load the project from the database file IGIDS is now available from The University of Texas at Austin s Civil Engineering Department s anonymous ftp site and will be made available by McTrans Ref 33 in the future The ftp site can be accessed by an Internet browser at ftp ftp ce utexas edu ftp igids or by the ftp program at ftp ce utexas edu with the igids directory then selected The igids directory contains documentation dos and winnt sub directories The DOS directory contains ustn40 ustn50 and ustn95 sub directories The winnt directory contains ustn50 and ustn95 subdirectories IGIDS uses a graphics engine MicroStation to perform all interactive graphics operations and to maintain the graphics engine database IGIDS software operates above and drives the graphics engine through a higher level language interface IGIDS allows the user to switch easily between executing IGIDS commands and graphics engine commands The commands available within the graphics engine are used for this purpose as much as possible IGIDS does not
42. ping Double Solid Line 150mm yellow 975 36 M Striping Solid Line 450 mm white 43 20 M Signal 3 lens vertical Signal 3 lens protected left vertical Channelization Left Controller Pretimed size 1 Channelization Right Channelization Straight HA I IS 00 IGIDS Traffic Inventory Report Interactive Graphics Intersection Design System Version 03 00 Current Date and Time 14 Jan 1998 14 08 09 Intersection Description Interactive Graphics Intersection Design System Alternative Description ce igids sys_data STD_5X5 DAT Alternative Number 1 Striping Solid Line 150 mm white 1990 17 M Striping Broken Line 150 mm white 2926 08 M Striping Double Solid Line 150 mm yellow 975 36 M Striping Solid Line 450 mm white 43 20 M Signal 3 lens vertical 8 Signal 3 lens protected left vertical 4 Channelization Left 4 Controller Pretimed size 1 1 Channelization Right 4 Channelization Straight 4 IGIDS Traffic Inventory Spreadsheet TRAINING An IGIDS Training Manual was developed in printed form using Microsoft Word and for use on the World Wide Web www HTML A Microsoft PowerPoint presentation was also developed that follows the Overview chapter of the IGIDS Training Manual The IGIDS Training Manual in printed or HTML form may be used in a self paced individual instruction mode or by an instructor
43. ption evaluation pollution analysis cost estimating and other engineering functions which are eventually reduced to practice in a set of plans and specifications Virtually all the engineering and analysis procedures needed to complete the design process are well known and documented IGIDS assists engineers in the analysis and design of isolated at grade intersections and operates on personal computers and workstations The role of IGIDS is to provide the intersection design engineer with suitable tools to assist with each process stage These tools may be loosely divided into three groups The first group includes the drawing tools IGIDS uses MicroStation as a graphics engine to perform all graphics input and output The user may select from an IGIDS library one of several typical intersection designs and then modify it as needed to define the particular intersection of interest Alternately the user may define the intersection geometry by pointing at selected elements in a reference file created by another source such as a topographical map of the area with optional use of a superimposed aerial photo Finally the user may create the key components of the intersection geometry on the scratch level using MicroStation commands with optional use of a superimposed aerial photo and then define the intersection geometry by pointing at these elements After the intersection leg centerlines have been defined IGIDS provides several commands by which
44. r can be placed by the user Next are the built in analysis tools Both graphical aids and computational analysis procedures are incorporated For standard AASHTO design vehicles vehicle turning templates Ref 31 may be quickly drawn to a user specified turn radius for the turn between adjacent user selected legs These templates may be moved dynamically over the intersection geometry to evaluate pavement edge and channelization requirements For checking horizontal sight distance restrictions sight lines for stopped vehicles yielding vehicles or vehicles approaching an uncontrolled intersection may be drawn For vertical sight obstruction checking within the horizontal sight distance triangle the triangle file created from a Digital Terrain Model DTM must be attached as a reference file and the user must be in a 3D MicroStation design file Procedures described in the 1994 Highway Capacity Manual Special Report 209 Ref 30 Chapter 9 Signalized Intersections may be used to identify v c ratios and delays for intersections with pretimed controllers IGIDS displays the v c ratios and delays in bar chart format for each leg An inventory or bill of materials for traffic control features can be requested in printed or spreadsheet compatible input file format Finally there are data manipulation tools that can be used to prepare data files for analyses that are executed outside IGIDS with the results then brought back into IGIDS The TEXAS
45. rds Intersection design Interactive Graphics Intersection No restrictions This document is available to the public through the Design System IGIDS National Technical Information Service Springfield Virginia 22161 19 Security Classif of report 20 Security Classif of this page 21 No of pages 22 Price Unclassified Unclassified 56 Form DOT F 1700 7 8 72 Reproduction of completed page authorized 18 Distribution Statement INTERACTIVE GRAPHICS INTERSECTION DESIGN SYSTEM IGIDS RESEARCH REPORT by Thomas W Rioux Robert F Inman Randy B Machemehl and Clyde E Lee Research Report Number 1291 2 Research Project 0 1291 Interactive Graphics Intersection Design System IGIDS Conducted for the TEXAS DEPARTMENT OF TRANSPORTATION in cooperation with the U S Department of Transportation Federal Highway Administration by the CENTER FOR TRANSPORTATION RESEARCH Bureau of Engineering Research THE UNIVERSITY OF TEXAS AT AUSTIN January 1998 This report was prepared in cooperation with the Texas Department of Transportation and the U S Department of Transportation Federal Highway Administration ACKNOWLEDGMENTS The authors express appreciation for the guidance provided by the TxDOT Project Director H Wickes TRF and by the Project Monitoring Committee which included J Barron Waco M Emery Tyler B Gilley Lubbock J Kelly Lubbock C Slacum Lufkin and E Sanchez El Paso
46. s stored in a database file All needed graphics are drawn as a part of this process Existing nonIGIDS graphics should be accessed as a reference file Reference files should be attached so that their elements can be snapped to and located Upon ending IGIDS or ending MicroStation IGIDS determines whether any data have been modified since any LOAD FROM gt DATABASE command or the last SAVE TO gt DATABASE command if modifications have been made IGIDS presents an Alert Box Pressing the OK push button will allow IGIDS to perform a SAVE TO gt DATABASE command whereas pressing the Cancel push button will cause IGIDS to exit without saving any data OBJECTIVES The primary objectives of Research Project 0 1291 were to provide 1 two additional functional features to the Interactive Graphics Intersection Design System IGIDS and 2 appropriate training resources that will acquaint potential users with IGIDS and its capabilities Explicit objectives were the following 1 Add a feature to IGIDS that will permit vertical alignment based sight distance checking 15 2 Add to IGIDS a capability allowing users to graphically place signs signals and pavement markings which are captured into a graphics file that can be plotted from IGIDS or from TxDOT s Automated Plan Preparation System APP 3 Generate a current bill of materials file as traffic control features are graphically placed by a user 4 Develop concepts and materials f
47. to place lanes and curb returns and to manipulate the various intersection elements The elements of the design may be specified by the most convenient method for the particular situation For example lane width may sometimes be specified by keyboard entry of a numerical value Or it may be more convenient to identify lane edge graphics in a file that is being viewed concurrently with the IGIDS graphics file Alternately requesting that the lane edges be located by identifying existing landmarks on a superimposed aerial photo may be most convenient Such traffic control features as stop signs yield signs signal controller cabinets channelization symbols and signal heads may be placed by the user Traffic data may be entered as turn movement volumes or as leg volumes with turn percentages using a dialog box Signal phasing is entered graphically while signal timing is entered via a dialog box Centerline lane edge and stop line striping may be added using other IGIDS elements Additional striping for islands tapers and gores may be created using graphical elements placed at the scratch level Striping types include solid line broken line dotted line lane drop no passing inbound no passing outbound double solid line and double broken line Striping widths are 100 150 200 300 450 and 600 mm 4 6 8 12 18 and 24 inches Striping colors are white and yellow Only valid combinations of striping type striping width and striping colo
48. tored in the host computer s memory This stored data are a complete record of the Intersection design Included are the attributes of each IGIDS object and how IGIDS objects are related data that have been calculated during the design process and data that have been entered manually by the user The data may be stored as a disk file and later retrieved The IGIDS database will be the master database All graphics and attribute data items will be contained in the IGIDS database and the value stored there will have precedence over any other value Thus the graphics engine database can be deleted or all of the graphics in the graphics engine database can be deleted or erased and IGIDS will be able to re create the graphics previously saved into an IGIDS database using the LOAD FROM gt DATABASE command Any graphics added by the user on the scratch level will be lost Any IGIDS vehicle turn template sight distance checking TEXAS Model statistics and Highway Capacity Manual Chapter 9 graphics will be lost but are easily re created from the IGIDS database information Coordinate distance angular and other data in the IGIDS database will be considered the definitive values IGIDS will always use the values in the IGIDS database for all calculations IGIDS will keep the entire IGIDS database in memory so that no disk I O will be involved in reading a data item this will allow the software to operate as fast as possible IGIDS presents this design to th
49. type numbers will be stored as 10 significant digit 32 bit integer variables All other integer numbers with no perceived possibility of exceeding several hundred will be stored as 5 significant digit 16 bit integer variables IGIDS uses relational hierarchical geometry Relational geometry refers to the fact that the only absolute coordinate needed by IGIDS is the center of the intersection The legs of the intersection are defined relative to the intersection center the lanes of a leg are then defined relative to the leg s centerline and so on IGIDS data are stored as objects with IGIDS maintaining the parent child relationships among IGIDS objects IGIDS works by manipulating a defined set of objects There is a strict set of rules used by IGIDS that fixes the way that these IGIDS objects are related to each other The task of complying with these rules is assigned to IGIDS so the user need not be concerned with the relationship details IGIDS defines the relative object for each type of IGIDS object IGIDS calculates the station and offset of a coordinate from the leg centerline for all items that are a child of the leg Only IGIDS commands can be used to manipulate the geometry because of the need to update the data in the IGIDS structures IGIDS minimizes requirements that the user enter data in a defined order or sequence To accomplish this objective IGIDS will automatically sort each list of children IGIDS objects as new children IGIDS o
50. ult will be the length of the reference object minus the trim length and 3 copy the reference object to IGIDS and apply the current attribute settings When in Modify Attributes Mode the Type of Striping Width in mm Color and Shift may be specified while the Reference Object Type is dimmed and not selectable The attributes of the selected stripe will be modified to the current values selected When in the Delete Mode the Type of Striping Width in mm Color Shift and the Reference Object are all dimmed and not selectable The selected stripe will be deleted with confirmation The following table defines the allowed combinations of striping type width and color 24 Striping Type 100 mm 150 mm 200 mm 4 inches 6 inches 8 inches Yes Yes Yes Yes Yes Yes solid line Yes Yes Yes No Yes No No Yes Yes Yes Yes IGIDS Allowed Combinations of Striping Type Width and Color Striping uses MicroStation custom line styles which are available only in MicroStation Version 5 0 and higher Custom line styles were developed for each striping type unit of measurement and width The stripe dimensions defined in the 1980 Texas Manual on Uniform Traffic Control Devices for Streets and Highways with Revision 6 1996 Ref 29 were used to create the custom line styles and to define the allowable combinations of striping type width and color The file igids ls rsc contains the IGIDS custom

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