DVRPC TMIP Peer Review Dynamic Traffic Assignment (DTA) Oct. 29 th, 2014

Why we used/need DTA  Used DTA for special applications:  Center City evacuation modeling  I-95 reconstruction analysis  Center City bridges reconstruction analysis  Other use cases  Always some construction projects in the region  Evaluate time-of-day tolling and other CMP strategies  Make full use of ABM (SHRP2 C10)

Center City Simulation Models  Model Area:  2x1 miles, 300+ signals 260,000+ jobs  Multi-tier model design  Multi-mode simulations  Used for modeling two emergency scenarios  Extended for bridge reconstruction analysis (ongoing project)

Intersection Modeling

Dynamic Traffic Assignment  VISUM DUE - macroscopic DTA  Use temporal profile (dynamic loading) approach  Use flow-density diagram  Model queue spillback  Accept time-varying attributes  Extended for pedestrian simulations

Multi-Mode Simulation

Example Outputs of DTA Bus Delay Auto Volume

Wishlist  Better intersection modeling  Better spill-back handling  Dynamic OD estimation capability  Modeling ITS strategies (e.g. VMS)  Simulation-based DTA  More accurate ?  Feasible (regional implementation) ?

I-95 Reconstruction Analysis  I-95 corridor  52-mile long,170,00 ADT  Analysis needs  Interchange reconfiguration alternatives analysis  Construction closure alternatives screening  Reconstruction plans and staging

I-95 Dynus-T Model  Model Spec  TIM 1.0 model area, 50,000 links, 2,000 zones  24-hour demand in 15-minute Intervals  Pros  Individual vehicles represented  Queue lengths are explicitly modeled  Routes updated during trip in response to encountered congestion  Better representation of signals and intersection operations

Regional DTALite Model

 Model Spec  TIM 2.0 model area, 256,000 links  4-hour AM period (5-million vehicles)  Pros  Use data hub (ease data transferability)  Modeling flexibility (Simplicity ->Complexity) Simple point queue-> spatial queue -> kinematic wave model Simple signal representation -> HCM type critical movement based signal timing optimization

DTA in TIM 3.0 ?  Model type  Analytical based  Simulation based  Where to use (in conjunction with ABM)  Highway assignment only  Highway skimming and assignment  Other issues  Model transfer / network synchronize  Run time  Calibration