1111111111111111111111111"1111
`PB95-266516
`
`TravTek
`System Architecture Evaluation
`
`Publication No. FHWA-RD-94-141
`
`July 1995
`
`u.s. Department of Transportation
`Federal Highway Administration
`
`Research and Development
`Turner-Fairbank Highway Research Center
`6300 Georgetown Pike
`McLean, Virginia 22101·2296
`
`ASUS-1015, Page 1
`
`

`

`FOREWORD
`
`This report is one of eight reports produced as part of the evaluation of the Travtek operational field
`test, conducted in Orlando, Florida, during 1992-1993. Travtek, short for Travel Technology, was an
`advanced driver information and traffic management system that provided a combination of traveler
`information services and route navigation and guidance support to the driver. Twelve individual but
`related studies were conducted during the evaluation. Evaluation goals and objectives were
`represented by the following basic questions: (1) Did the TravTek system work? (2) Did drivers save
`time and avoid congestion? (3) Will drivers use the system? (4) How effective was voice guidance
`compared to moving map and turn-by-turn displays? (5) Was TravTek safe? (6) Could TravTek
`benefit travelers who do not have the TravTek system? (7) Will people be willing to pay for TravTek
`features?
`
`Evaluation data were obtained from more than 4,000 volunteer drivers during the operation of 100
`specially equipped automobiles for a 1-year period. Results of the evaluation demonstrated and
`validated the concept of in-vehicle navigation and the provision of traveler information services to
`the driver. The test also provided valuable results concerning the drivers' interaction with and use
`of the in-vehicle displays. This project has made many important contributions supporting the goals
`and objectives of the Intelligent Transportation sYstem~program.'\
`//~'rL-
`~.~~_.'
`LXSaxton, Direct r
`
`Office of Safety and Traffic
`Operations Research and Development
`
`NOTICE
`
`This document is disseminated under the sponsorship of the Department of Transportation in the
`interest of information exchange. The United States Government assumes no liability for the
`contents or the use thereof. This report does not constitute a standard, specification, or regulation.
`
`Trade and
`The United States Government does not endorse products of manufacturers.
`manufacturers' names appear in this report only because they are considered essential to the object
`of the document.
`
`ASUS-1015, Page 2
`
`

`

`IL. ~overnmemAccession No.
`
`1. Kepon: NO.
`FlfVV1\-FU)-94-141
`14. TItle and Subtitle
`TravTek SYSTEM ARCIDTECTURE EVi\LU1\TION
`
`7. Author(s)
`C. Blumentritt. K. Balke E. Seymour. R. Sanchez
`9. Performing Organization Name and Address
`texas Transportation Institute
`8150 North Central Expressway, Suite 815
`Dallas, Texas 75206
`
`12. Sponsoring Agency Name and Address
`Office of Safety and Traffic Operations R&D
`Federal Highway 1\dministration, 6300 Georgetown Pike
`McLean, V1\ 22101-2296
`
`15. Supplementary Notes
`
`rtO
`IR
`T h·
`ocumen
`ec mea
`eDOI
`".
`I"<eclplenrs t;atalog NO.
`
`P
`Ion age
`tat"
`
`b.
`
`o.
`
`I"<eport uate
`July ]995
`t-'errormlng urganlzatlon (.;oae
`
`o.
`
`I"'enormlng urganlzauon t<.epon: 1\10.
`
`10. Work Unit No. (TRAIS)
`3B71\
`11. Contract or Grant No.
`DTFH61-91-C-00106
`13.Type of Report and Period Covered
`Final Report
`11/91 - 3/94
`14. Sponsoring Agency Code
`
`Contracting Officer's Technical Representative (COTR) - Frank Mammano, HSR-12
`
`16. Abstract
`The TravTek System i\rchitecture Evaluation documents in detail the TravTek system,
`including the Traffic Information Network (TIN), TravTek Information Services Center (TISC),
`Traffic Management Center (TMC), and the TravTek vehicle. The TravTek system achieved a high
`state of automation. Link travel time data were received automatically from the probe vehicles,
`freeway management system, and arterial control management system. These data were fused and
`distributed to the vehicles, all without operator intervention. The process for estimating link travel
`times worked well on the basis of information available. TravTek needed more high quality traffic
`information to/provide vehicle routing that had the benefit of accurate, up to minute traffic
`information: Probe vehicles provided reliable travel times, but reported significant travel time
`variations on arterial links due to stop time at intersections.
`Incident information available to
`TravTek was sparse and usually not timely. Historical link travel time, map, and local information
`data base accuracy was good.
`1\ human factors study, regarding the TMC operation and
`environment, found operator improvement was needed. The TravTek system was very reliable,
`largely due to a distributed architecture.
`Problems with the TravTek system were largely
`implementation related, as opposed to architecture related. Lessons learned during TravTek are
`enumerated, and conclusions are stated which sustain the over~l success of TravTek.
`
`17. Key Words '
`TravTek, 1\TIS, IVHS i\rchitecture,
`i\rchitecture Evaluation
`
`18. Distribution St~tement
`No restrictions. This document is available to the
`public through the National Technical
`Information Service, Springfield, Virginia 22161
`
`19. Security Classif. (of this report)
`Unclassified
`
`20. Security Classif. (of this page)
`Unclassified
`
`21. No. of Pages
`250
`
`22. Price
`
`Form DOT F 1700.7
`
`(8-72)
`
`Reproduction of completed page authorized
`
`ASUS-1015, Page 3
`
`

`

`

`

`PREFACE
`
`TravTek was a joint public sector - private sector project to develop, test and evaluate an
`integrated driver information system and supporting infrastructure in metropolitan Orlando,
`Florida. TravTek provided motorists with navigation, real-time traffic information, route
`selection and guidance, and motorist information services. TravTek systems were installed in 100
`1992 Oldsmobile Toronados operating in a 1900 km2 area surrounding Orlando. Seventy-five of
`the cars were in a car rental fleet for use by visitors to Orlando and 25 ofthe cars were used by
`local residents and for special controlled tests.
`
`The project was the largest, most comprehensive advanced driver information system project
`to date attempted in the United States. It officially started on March 23, 1992 and operated for 1
`year. TravTek was a partnership between the private sector, represented by General Motors and
`the American Automobile Association, and the public sector, represented by the Federal Highway
`Administration, the Florida Department of Transportation, and the City of Orlando. Additional
`private sector participants included Motorola and Avis.
`
`The TravTek evaluation consisted of a series of connected research efforts that addressed
`every facet ofthe system. This effort was organized as a collection ofmajor tasks. Task A was
`the Project Management task, and coordinated all efforts ofthe evaluation team, as well as
`provided liaison with the TravTek partners. Task B included the Rental User Study, to evaluate
`the drivers' impressions ofTravTek, and the Local User Study, to evaluate the participation of
`local users in longer term experiments. Task C included the Yoked Driver Study, to evaluate the
`relationship between use ofthe TravTek functions and measures of driver/vehicle performance,
`the Orlando Traffic Network study, to evaluate alternative TravTekidriver interface features, and
`the Camera Car Study, to examine driver interactions with different versions ofthe TravTek in(cid:173)
`to gather qualitative
`vehicle system. Task D included the Debriefing and Interview Study,
`information from participants, and the Questionnaire Study, to obtain user perceptions from a
`wider range of attributes. Task E included the TravTek Modeling Study, to model the traffic and
`safety performance ofthe TravTek system, and the Safety Study, to evaluate the safety ofusing
`in-vehicle information systems. Task F was the System Architecture Study, to evaluate all aspects
`ofthe TravTek system design.
`
`This report presents the results ofthe Task F System Architecture Evaluation. It documents
`in detail the TravTek system, including the Traffic Information Network (TIN), TravTek
`Information Services Center (TISC), Traffic Management Center (TMC), and the TravTek
`Vehicle. Each ofthese system entities has an overall description, and in turn each entity has a
`detailed functional description, a process description, and data flow diagrams. Issues addressed in
`the system architecture evaluation include: accuracy ofthe link travel times provided by the
`various real-time sources; accuracy and timeliness ofthe incident information broadcast to the
`TravTek vehicles; data base accuracy; performance ofthe data fusion process; system operation
`considerations: evaluation ofoperator interface, network covering, and degree of automation;
`reliability of subsystems, TMC/vehicle communications, and software; and system architecture
`features. The lessons learned during TravTek are given, and conclusions are stated which sustain
`the overall success ofTravTek.
`
`111
`
`ASUS-1015, Page 5
`
`

`

`TABLE OF CONTENTS
`
`Section
`
`,
`
`IN"TRODUCTION
`; . . . . . . . . .. 1
`TravTek BACKGROUND
`1
`TravTek EVALUATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . .. 3
`TravTek ARCHITECTURE EVALUATION OBJECTIVES. . . . . . . . . . . . . . . .. 6
`SYSTEM OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 9
`TRAFFIC IN"FORMATION NETWORK (TIN)
`10
`TravTek IN"FORMATION AND SERVICES CENTER (TISC)
`,. . . . ..
`11
`TRAFFIC MANAGEMENT CENTER (TMC) . . . . . . . . . . . . . . . . . . . . . . . . . .. 12
`TravTek VEHICLE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 12
`TELECOMMUNICATIONS
`16
`SYSTEM DESCRIPTION
`17
`TRAFFIC IN"FORMATION NETWORK (TIN) .. . . . . . . . . . . . . . . . . . . . . . . .. 17
`TIN" Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
`18
`Link Travel Times. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 19
`Incident and Congestion Reporting. . . . . . . . . . . . . . . . . . . . . . . . . .. 20
`Information Dissemination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 24
`TravTek IN"FORMATION AND SERVICES CENTER (TISC) . . . . . . . . . . . ... 26
`TISC Functional Description . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . .. 27
`TISC Process Description
`30
`TISC Data Flow
`; . . . . . . . . . .. 30
`TRAFFIC MANAGEMENT CENTER (TMC) . . . . . . . . . . . . . . . . . .. . . . . . . .. 30
`TMC Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 33
`34
`Traffic Information Collection
`Data Logging
`35
`Traffic Data Fusion
`38
`Traffic Information Dissemination
`41
`Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 42
`49
`Operator Interface
`TravTek VEHICLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 53
`TravTek Vehicle Functional Description
`56
`Navigation
`57
`Route Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
`59
`62
`RoureGuidance
`LocaIInformation
`65
`66
`DriverInrerface
`Vehicle Probe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 69
`Data Logging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 70
`
`IV
`
`ASUS-1015, Page 6
`
`

`

`TABLE OF CONTENTS
`(continued)
`
`Section
`
`QUALITY OF TRAFFIC AND TRAVEL INFORMATION
`75
`QUALITY OF TRAVEL TIME INFORMATION
`;... 75
`Evaluation Methodology
`77
`Data Sources. . . . . . . . . . .. . . . . . . . . . . . . . .. . . .. . . . . . . . . . . . . . . . . .. 78
`Results . . .'. '.. '. . . . .. . . . :. . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . .. . .' . . .. 78
`"
`, 78
`System Performance
`, 83
`Source Errors
`QUALITY OF INCIDENT INFORMATION
`'...... ..•. . . . .. 96
`Evaluation Methodology
`,'~ . . . .. 97
`Data Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . .. . .. . . . .. 97
`Results . . . . . . . . . . . . . . . . . . . . . . . . . . . : . . . . . . . . . . . . . .'.'. . ". ..' ".'. . ., 98
`DATA BASE ACCURACY
`101
`Historical Data Base . . . . . . . . . . . . . . . . . . . . . . . . . .. . . .. . . . .. . . . . ..
`101
`Map Data Base . . . .. . . . . . . . . . . . . . . . . .. . . . . . . . . . ..
`102
`Local Information Data Base . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
`103
`EVALUATION OF THEDATA FUSION PROCESS
`107
`DATA FUSION PROCESS
`;
`107
`Evaluation Methodology
`111
`'...
`Data Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ; . . . . . . . . . . . ..
`111
`Results. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 112
`EVALUATION OF SYSTEM AND NETWORK OPERATIONS. . . . . .. . . . . . . . . .. 119
`TMC OPERATOR INTERFACE
`119
`Method. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . .. 119
`120
`Information Analysis
`Job Analysis . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . ..
`120
`120
`Workload Analysis
`Results
`121
`"
`".'
`121
`Information Flow Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
`123
`Job Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
`126
`Workload Analysis
`Discussion . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 130
`Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
`131
`NETWORK COVERING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
`131
`Network Description
`131
`Data Sources . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . ..
`131
`Probe Vehicle Activity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 134
`Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
`141
`Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
`141
`DEGREE OF AUTOMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
`143
`Discussion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
`143
`
`v
`
`ASUS-1015, Page 7
`
`

`

`TABLE OF CONTENTS
`(continued)
`
`Section
`
`147
`SYSTEM RELIABILITY
`147
`SUBSYSTEM RELIABILITY
`Data Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 147
`147
`Manual and Computer Generated Logs
`Log Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
`Onsite Interviews ofKey TravTek Participants . . . . . . . . . . . . . . . .. 150
`Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
`151
`151
`Results: June 1 Through December 31, 1992
`151
`Number ofFailures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
`152
`Duration ofFailures
`156
`Time ofDay Failures
`160
`Results: January 1 Through March 31, 1993
`Number ofFailures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 160
`160
`Duration ofFailures
`164
`Time ofDay Failures
`168
`Results: June 1, 1992 Through March 31, 1993
`Number ofFailures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 168
`171
`Duration ofFailures
`175
`Time ofDay Failures
`Onsite Interview Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 179
`Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 180
`TMCNEHICLE COMMUNICATION SUBSYSTEM RELIABILITY . . . . . .. 180
`Evaluation Methodology
`180
`Data Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
`181
`Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 182
`SOFTWARE RELIABILITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 190
`195
`SYSTEM ARCHITECTURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
`TravTek DISTRIBUTED ARCHITECTURE
`195
`CENTRAL ARCHITECTURE DESIGN ALTERNATIVE
`196
`RELATIONSHIP OF TravTek ARCHITECTURE TO PROBLEMS
`199
`CRITIQUE OF IMPLEMENTATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 199
`COMMUNICATION SYSTEM ALTERNATIVES. . . . . . . . . . . . . . . . . . . . . .. 201
`IMPLEMENTATION CRITERIA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 202
`LESSONS LEARNED. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 205
`LIST OF LESSONS LEARNED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 205
`Lesson # 1: Truncated Test Period . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 205
`Lesson # 2: Diagnostic Information in Distributed System . . . . . . . . . .. 205
`Lesson # 3: Improve Degree of Automation . . . . . . . . . . . . . . . . . . . . . .. 205
`Lesson # 4: Map Data Bases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 205
`Lesson # 5: Dual Map Data Bases in Vehicle . . . . . . . . . . . . . . . . . . . . .. 206
`Lesson # 6: Manual Record Keeping. . . . . . . . . . . . . . . . . . . . . . . . . . .. 206
`
`VI
`
`ASUS-1015, Page 8
`
`

`

`TABLE OF CONTENTS
`(continued)
`
`Section
`
`LESSONS LEARNED (Continued)
`
`Lesson # 7: Quality of Travel Information . . . . . . . . . . . . . . . . . . . . . . .. 206
`Lesson # 8: TMC Manual Record Keeping
`206
`Lesson # 9: TIN Network Concept
`. . . . . . . . . . . . . . . .. 206
`Lesson # 10: Traffic Data Timeliness. . . . . . . . . . . . . . . . . . . . . . . . . . .. 207
`Lesson # 11: PubliclPrivate Partnership
`207
`Lesson # 12: Development of Evaluation Plans . . . . . . . . . . . . . . . . . . .. 207
`Lesson # 13: Timeliness and Quality of Incident Information
`207
`Lesson # 14:
`Importance of Machine Logs. . . . . . . . . . . . . . . . . . . . . .. 208
`Lesson # 15:
`Involvment of Project Personnel. . . . . . . . . . . . . . . . . . . .. 208
`Lesson # 16: Performance of Distributed System
`208
`Lesson # 17: Operation of Complex System
`208
`Lesson # 18: Benefits of ATIS to Traffic Mangement . . . . . . . . . . . . . .. 208
`Lesson # 19: Acceptable Level of Operation
`. . . . . . . . . . . . . . .. 208
`Lesson # 20: Timely Processing of Log Data . . . . . . . . . . . . . . . . . . . . .. 209
`SUGGESTIONS FOR FURTHER DATA EVALUATIONS. . . . . . . . . . . . . . .. 209
`CONCLUSIONS
`211
`APPENDIX A. TMC SYSTEM HARDWARE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 213
`APPENDIX B. TMC OPERATOR MENU FUNCTIONS. . . . . . . . . . . . . . . . . . . . . .. 215
`APPENDIX C. DATA BASE OF TravTek AND FMC INCIDENTS
`(JANUARY 22, 1993 THROUGH MARCH 26, 1993) . . . . . . . . . . . . . . . . . . . .. 225
`APPENDIX D. PROBE VEHICLE FREQUENCY BY MONTH
`229
`REFERENCES
`235
`
`VB
`
`ASUS-1015, Page 9
`
`

`

`Figure No.
`
`LIST OF FIGURES
`
`1.
`2.
`3.
`4.
`5.
`6.
`7.
`8.
`9.
`10.
`11.
`12.
`13.
`14.
`15.
`16.
`17.
`18.
`19.
`20.
`21.
`22.
`23.
`24.
`25.
`26.
`27.
`28.
`29.
`30.
`31.
`32.
`33.
`34.
`35.
`36.
`37.
`38.
`39.
`40.
`
`2
`TravTek geographic area
`TravTek system diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 9
`Traffic management center location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
`13
`Vehicle information flow. . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . ..
`15
`Elements oftraffic information network
`18
`Illustration oftravel time reporting function
`20
`Data flow requirements for travel time reporting function . . . . . . . . . . . . . . . . . . .. 21
`Illustration of moderate and heavy congestion levels ... . . . . . . . . . . . . . . . . . . . .. 23
`Functional diagram ofincidentlcongestion reporting task·. . . . . . . . . . . . . . . . . . . .. 24
`Data flow requirements for reporting incidents and congestion
`25
`Functional diagram of information dissemination process . . . . . . . . . . . . . . . . . . . .. 25
`Data flow requirements for disseminating travel time and incident information. . . .. 26
`TISC system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 28
`TISC help desk information flow. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 31
`TMC computer configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 32
`TMC basic system configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 32
`Traffic information collection data flow diagram
`: . . . . . . . . . .. 35
`TMC log data distribution path. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 38
`Vehicle log data distribution path
`39
`TMC data fusion process data flow (all links updated each minute) . . . . . . . . . . . .. 41
`Traffic dissemination function data flow
`43
`TMC/vehicle data radio system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 48
`TMC communications data flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 49
`TMC operator screen display (typical) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 51
`TMC operator menu selection diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 53
`TMC operator interaction process data flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 54
`TravTek vehicle architecture. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 55
`Layout ofthe TravTek equipment in the vehicle
`55
`Interactions between TravTek vehicle functions
`57
`Vehicle positioning function
`58
`Vehicle navigation data flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 59
`Vehicle route planning/route selection function. . . . . . . . . . . . . . . . . . . . . . . . . . .. 61
`Illustration of route selection process for rerouting . . . . . . . . . . . . . . . . . . . . . . . .. 63
`Route selection data flow
`63
`Route guidance functional diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 64
`Route guidance data flow
`65
`Local information functional diagram
`66
`Local information data flow
`66
`Driver interface function diagram
`68
`Data flow diagram for driver interface function. . . . . . . . .. . . . . . . . . . . . . . . . . .. 69
`
`V1l1
`
`ASUS-1015, Page 10
`
`

`

`Figure No.
`
`LIST OF FIGURES
`(Continued)
`
`41.
`42.
`43.
`44.
`45.
`46.
`47.
`48.
`49.
`50.
`51.
`
`52.
`
`53.
`
`54.
`
`55.
`
`56.
`
`57.
`
`58.
`59.
`60.
`61.
`
`62.
`
`63.
`64.
`65.
`66.
`
`Vehicle probe function
`70
`71
`Probe report data flow
`72
`Data logging function diagram
`In-vehicle data logging data flow. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 73
`Distribution ofwinning travel time sources for instrumented arterial links
`79
`Distribution ofwinning travel time sources for non-instrumented arterial links . . . .. 80
`Distribution ofwinning travel time sources on instrumented freeway links. . . . . . .. 81
`Distribution ofwinning travel time sources on non-instrumented freeway links ..... 82
`Relative error of sources of travel time information on freeway links . . . . . . . . . . .. 86
`Relative error of sources oftravel time information on arterial links . . . . . . . . . . . .. 87
`Correlation between travel times estimated using speed information from
`freeway surveillance system and probe-measured travel times during AM
`peak periods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 90
`Correlation between travel times estimated using speed information from
`freeway surveillance system and probe-measured travel times during
`Off peak periods . . . ..... " . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 91
`Correlation between travel times estimated using speed information from
`freeway surveillance system and probe-measured travel times during PM
`peak periods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 92
`Correlation between travel times estimated using delay measurements from
`computerized traffic signal system (UTCS) and probe-measured travel times
`during AM peak periods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 93
`Correlation between travel times estimated using delay measurements from
`computerized traffic signal system (UTCS) and probe-measured travel times
`during Offpeak periods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 94
`Correlation between travel times estimated using delay measurements from
`computerized traffic signal system (UTCS) and probe-measured travel times
`during PM peak periods
`Type of incident information logged at the TravTek traffic management center
`99
`(TMC)
`104
`Versions of navigation map data bases
`Versions of routing map data bases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 104
`Versions oflocal information data bases
`105
`Illustration of data fusion process on non-instrumented TravTek traffic
`network link ..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 109
`Illustration of data fusion process on link covered by real-time surveillance
`system (UTCS or freeway surveillance system) . . . . . . . . . . . . . . . . . . . . . . . . . .. 110
`Relative error rates for each iteration ofthe data fusion process in the Offpeak . .. 116
`Relative error rates for each iteration ofthe data fusion process inthe AM peak ., 117
`Relative error rates for each iteration ofthe data fusion process in the PM peak .. 118
`Greater Orlando road map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 132
`
`95
`
`IX
`
`ASUS-1015, Page 11
`
`

`

`Figure No.
`
`LIST OF FIGURES
`(Continued)
`
`67.
`68.
`69.
`70.
`71.
`72.
`73.
`74.
`75.
`76.
`
`77.
`78.
`79.
`80.
`81.
`82.
`83.
`84.
`85.
`86.
`87.
`88.
`89.
`90.
`91.
`92.
`93.
`94.
`95.
`96.
`97.
`98.
`99.
`100.
`101.
`102.
`103.
`104.
`105.
`106.
`
`;
`
`, 133
`TravTek traffic link network
`134
`Number oflinks by roadway type
`, 134
`"
`Link category distribution by distance
`TravTek vehicle probe reports ...................................•.... , 135
`TravTek traffic network - daily average link km
`135
`TravTek traffic network - monthly average link km
`, 136
`Links without probe vehicle traffic by month
`, 136
`Probe vehicle volumes band map - total during operational test
`, 138
`Probe vehicle mileage distribution by month
`139
`Plot of coordinates reported by vehicles for 10 days during month of
`140
`September, 1992 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .,
`142
`Illustration of route preference
`, 152
`Frequency offailures by subsystem, 6/92 - 12/92
`, 153
`Down times for all subsystems, 6/92 - 12/92
`, 153
`Down times for the UTCS subsystem, 6/92 - 12/92
`, 154
`Down times for the FMC subsystem, 6/92 - 12/92
`154
`Down times for the TIN subsystem, 6/92 - 12/92
`Down times for the TIse subsystem, 6/92 - 12/92
`155
`155
`Down times for the Radio subsystem, 6/92 - 12/92
`, 157
`Frequency offailures by time of day for all subsystems, 6/92 - 12/92
`Frequency of failures by time of day for UTeS subsystem, 6/92 - 12/92
`157
`158
`Frequency offailures by time of day for FMC subsystem, 6/92 - 12/92
`, 158
`Frequency offailures by time of day for TIN subsystem, 6/92 - 12/92
`159
`Frequency of failures by time of day for TISC subsystem, 6/92 - 12/92
`Frequency offailures by time of day for Radio subsystem, 6/92 - 12/92
`, 159
`Frequency offailures by subsystem, 1/93 - 3/93 . . . . . . . . . . . . . . . . . . . . . . . . . .. 160
`Down times for all subsystems, 1/93 - 3/93
`161
`Down times for UTCS subsystem, 1/93 - 3/93
`, 161
`Down times for FMC subsystem, 1/93 - 3/93
`162
`Down times for TIN subsystem, 1/93 - 3/93
`162
`Down times for TISC subsystem, 1/93 - 3/93
`163
`Down times for the Radio subsystem, 1/93 - 3/93
`163
`Time of day offailures for all subsystems, 1/93 - 3/93
`, 165
`Time of day offailures for UTCS subsystem, 1/93 - 3/93
`165
`Time of day offailures for FMC subsystem, 1/93 - 3/93
`166
`Time of day offailures for TIN subsystem, 1/93 - 3/93
`166
`Time of day of failures for TIse subsystem, 1/93 - 3/93
`167
`Time of day of failures for Radio subsystem, 1/93 - 3/93
`. . . . . . . . . . . . .. 167
`Frequency offailures by subsystem, 6/92 - 3/93
`, 168
`Frequency of failure by month for all subsystems
`, 169
`Failure frequency by month for the UTCS subsystem. . . . . . . . . . . . . . . . . . . . . .. 169
`
`x
`
`ASUS-1015, Page 12
`
`

`

`Figure No.
`
`LIST OF FIGURES
`(Continued)
`
`107.
`108.
`109.
`110.
`111.
`112.
`113.
`114.
`115.
`116.
`117.
`118.
`119.
`120.
`121.
`122.
`123.
`124.
`125.
`126.
`127.
`128.
`129.
`130.
`131.
`132.
`133.
`134.
`135.
`136.
`137.
`138.
`139.
`140.
`141.
`
`"
`
`Frequency of failures by month for the FMC subsystem . . . . . . . . . . . . . . . . . . . .. 170
`Frequency of failures by month for the TIN subsystem
`170
`Frequency offailures by month for the Radio subsystem
`171
`Down times for all systems
`172
`Down times for the UTCS subsystem
`173
`. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
`Down times for the FMC subsystem
`173
`Minimum, average, and maximum down times
`174
`"
`Minimum, average, and maximum down times by subsystem
`174
`Time of day of all subsystem failures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 176
`Time of day ofUTCS subsystem failures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 176
`Time of day ofFMC subsystem failures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 177
`Time of day of TIN subsystem failures
`177
`Time of day of TISC subsystem failures
`178
`Time of day ofRadio subsystem failures
`178
`Percent downtime by subsystem by month . . . . . . . . . . . . . . . . . . . . . . . . . . . . . "
`180
`Percentage ofTMC to vehicle communications failures
`"
`182
`Percentage ofvehicle to TMC communications failures. . . . . . . . . . . . . . . . . . . .. 183
`Percentage ofTMC to vehicle communications failures by month . . . . . . . . . . . ..
`183
`Percentage ofvehicle to TMC communications failures by month . . . . . . . . . . . .. 184
`Vehicle transmit time slot accuracy
`"
`185
`Location ofvehicles with successful TMC to vehicle communications
`"
`186
`Location ofvehicles with unsuccessful TMC to vehicle communications
`"
`187
`Location ofvehicles with successful vehicle to TMC communications
`"
`188
`Location ofvehicles with unsuccessful vehicle to TMC communications
`"
`189
`TravTek vehicle program version service times
`"
`192
`Probe vehicle frequency, June 1992
`"
`229
`Probe vehicle frequency, July 1992
`"
`229
`Probe vehicle frequency, August 1992
`"
`230
`Probe vehicle frequency, September 1992 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 230
`Probe vehicle frequency, October 1992
`"
`231
`Probe vehicle frequency, November 1992
`231
`Probe vehicle frequency, December 1992
`232
`Probe vehicle frequency, January 1993
`232
`Probe vehicle frequency, February 1993
`233
`Probe vehicle frequency, March 1993
`233
`
`xi
`
`ASUS-1015, Page 13
`
`

`

`Table No.
`
`LIST OF TABLES
`
`1.
`2.
`3.
`4.
`5.
`6.
`7.
`8.
`
`9.
`10.
`11.
`12.
`
`13.
`
`14.
`
`15.
`16.
`17.
`18.
`19.
`20.
`21.
`22.
`23.
`24.
`25.
`26.
`27.
`28.
`29.
`30.
`31.
`32.
`33.
`34.
`
`xu
`
`;....
`
`11
`".. . . ..
`TravTek TIN network user station list (as of 4/8/92)
`TISC staffing ..............................................;...... 27
`TMC operator schedule
`,......................... 33
`.
`,.
`Dynamic link time message ratios
`.
`,
`, ,
`; . .. 45
`Tasks performed by each ofthe TravTek vehicle. computers
`.,. 56
`Relative error of sources oftravel time information for arterial links
`84
`Relative error of sources oftravel time information for freeway links. . . . . . . . . . .. 85
`Correlation between travel time estimates produced by probes and those
`produced by real-time surveillance systems
`89
`, 100
`Peak period incidents on 1-4 logged by the TravTek system
`101
`Delays in incident information in TravTek system
`Default quality and age values assigned to travel time sources . . . . . . . . . . . . . . ., 108
`Relative error of probe-measured travel times to travel times measured by
`surveillance system each minute in data fusion on freeway links during AM
`peak periods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . .,
`Relative error of probe-measured travel times to travel times measured by
`surveillance system each minute in data fusion on freeway links during
`Offpeak periods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....