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Dynamic Traffic Assignment and Applications in the Twin Cities Area Steve Wilson SRF Consulting Group Duluth, Minnesota August, 2008 Outline Background/FHWA Support 35W Bridge Project Test Applications FHWA DTA Ongoing Development What is Dynamic Traffic Assignment (DTA)? Mesoscopic traffic assignment model – More responsive to operational factors (queuing) than traditional travel demand models – More responsive to system level factors (route-changing) than traditional operations models Travel Demand Model Assignment Limitations Trips are instantaneously on all links between origin to destination (not time-dependent) Congestion delay does not adequately reflect bottlenecks (upstream or downstream) DTA Models Availability Federal Highways DTA Commercial Vendors – CITILABS – TRANSCAD – PTV – EMME/2 – Others FHWA DTA (TrEPS) Program Started in 1995 Two parallel tracks (Real-time ITS and Operational Planning) Linking planning and operations – Concept of “Operational Planning” Fill in the traffic analysis tool gap – Macroscopic (static, regional) – Mesoscopic (dynamic, regional) – Microscopic (dynamic, corridor) Integration with TDM and microscopic model Program Activities DTA concept education and outreach – Webinars (online) – several per year – Short seminar (0.5-1 day) – on demand – Workshops (2.5 day) – 2 to 3 per year Mn/DOT (September 2008) Program Activities Technical support to state agencies – MPO/DOT – FHWA division – Resource center – FHWA HQ or TFHRC – Educational Support Training for DTA concepts – Modeling Support Assist in initial modeling and dataset buildup Can be extended to consultants for a federally funded project Matching-fund may be needed if more involvement is requested M&O Status (updated May 2008) State Users Workshops held Future Workshops (TBD) Initial Development of Twin Cities FHWA DTA Model I-35W Bridge Collapse FHWA Response Pace of Study MnDOT Model Development Importing of regional TDF model network Importing of regional TDF model trip tables Network cleaning Simplified traffic control assumptions MnDOT Model Development Calibration/adjustment of O-D matrices Testing of routing/improvement scenarios Initial Development of Twin Cities FHWA DTA Model I-35W Bridge Collapse FHWA Response Pace of Study I-35W UPA Project UPA Program Competition Innovative, multimodal, priced Open by end of 2009 I-35W UPA Project Priced dynamic shoulder lane segment Addition of a HOT lane in Crosstown reconstruction project Conversion of existing HOV lane to HOT lane Also: BRT advanced implementation, park-ride, ITS Why Dynamic Traffic Assignment? Availability Better MOEs for comparison of Alternatives High-level operational evaluation HOT lane capabilities Why Not Dynamic Traffic Assignment? Availability/readiness Memory/CPU resources Learning curve Traffic engineers’ comfort zone Analysis (Top 20 O-D pairs impacted by bridge collapse) 119 123 124 443 444 426 424 423 414 359 371 372 373 337 334 337 335336 339 340 341 322321 318 514 421 420 Twin Cities FHWA DTA Model Departure Time (min) 230 210 190 170 150 130 110 90 70 50 30 10 10 0 w Departure Time (min) wo Departure Time (min) Total 20 230 30 210 40 190 50 170 60 150 408 230 210 190 170 150 130 110 90 409 130 wo 110 w 70 0 90 10 50 20 70 30 30 40 50 Departure Time(min) 10 50 Travel Time (min) 60 30 70 Travel Time (min) 230 210 190 170 150 130 110 90 70 50 30 10 Travel Time (min) 70 10 Travel Time (min) Travel time into Downtown area 410 90 80 70 60 50 40 30 20 10 0 w 407 wo 70 60 50 40 30 20 10 0 w wo FHWA DTA Model (Subarea) Learning Curve “CORSIM-like” Wiki help system Model Integration w/ TDF softwares FHWA DTA HOT Lane Options Distance-based Link-based Zone-based (coming soon) FHWA DTA HOT Lane Options Flexibility Multiple User Class Flexibility Flexible Traffic Flow Model Exportable Tabular Output Graphic Output Time Stream Comparisons FHWA DTA Tests (with subarea model) Sensitivity to geometric changes – Through lane add – Auxiliary lane add – Bottleneck queuing Stadium event departure Peak-segment ramp O-D volumes Best Candidate DTA Uses Evacuation Planning Work zones Systems Planning Value pricing/HOT Lanes Benefit-Cost Analysis Travel demand model feedback Lessons Learned New DTA model not short-term response Integration with planning/simulation models Role of DTA in project development process FHWA DTA V2.0 Modeling Features Lane-group based Anisotropic Mesoscopic Simulation (AMS) models Relative gap gradient based assignment algorithm Epoch implementation for 24-hour to multi-day assignment Destination and origin-based time-dependent leastcost path algorithms for various applications Vertical integration with TDM and VISSIM 2008 Projects and Applications Outlook In progress – Military Deployment Transportation Improvement in Guam (PB, FHWA) – Interstate highway corridor improvement (TTI, TxDOT, ELPMPO) – Value Pricing (ORNL, FHWA; SRF, Mn/DOT, TTI, TxDOT) – Evacuation operational planning (UA, ADOT; LSU, LDOT; Noblis, FHWA; U of Toronto) – Integrated Corridor Management modeling (CS, FHWA) – Bay area regional modeling (CS, MTC) – Florida turnpike system traffic and evacuation analysis (FDOT Turnpike) – Commercial development traffic improvement (PAG) Future Outreach Activities Arizona – Workshop (July 29-31, jointly funded by MAG and FHWA) Minnesota – Mn/DOT workshop (September 09) California – CalTrans and CA MPOs (August 11-13, 2008) 2-3 Kick-the-Tire webinars (FY 09) 2-3 Training workshops (FY 09) FHWA DTA V2.0 Modeling Features Suite of supporting tools to facilitate model use: – Pre-processing Network cleaning Demand integration – Post-processing Time-space diagrams Time-varying link statistics reports Cumulative arrival curves Impacted vehicle analysis Vehicle path analysis Acknowledgements FHWA – Jim McCarthy – Chung Tran Mn/DOT Planning Division – Brian Isaacson – Mark Filipi – Tony Fischer DynusT Labs – Yi-Chang Chiu, University of Arizona Questions? Steve Wilson [email protected]