TO:    Freeway Operations Simulation Subcommittee Members and Friends

 The committee met on Sunday, January 21, 2007.  Based on the sign-up sheets, a total of 42 people attended.

As, planned, the focus of the meeting was the computer on simulation modeling of High Occupancy Toll (HOT) lanes.  We were able to have all eight presentations listed below in 75 minutes.

• Jaime Barcelo – Aimsun NG, TSS, Spain
• Michael Mahut – Dynameq, INRO, Canada
• Yi-Chang Chiu – DYNASMART-P, University of Arizona
• Hesham Rakha – Integration, Virginia Tech
• Haris N. Koutsopoulos, Northeastern University and Valibhav Rathi, MIT – MITSim Lab
• Pete Sykes – PARAMICS, SIAS, UK
• Daniel Morgan – TransModeler, Caliper Corp.
• Jim Dale – VISSIM, PTV America

All models seem to be well suited to represent a variety of high and low occupancy categories using vehicle classes or similar definitions. Tolling scheme representations and motorist reaction to tolling are a far more complex issue.  Some of the difficulties in modeling HOT lanes is toll pricing over time and its dynamic impact on the amount of motorists entering the HOT facility or remaining on the adjacent free facilities.  Variable toll pricing is determined endogenously or exogenously, but in the current state-of-the-art, pricing is an exogenous input or assumption in most traffic models.

The subcommittee plans to develop a paper session on Freeway Simulation of HOT and Managed Lanes for TRB 2008.  Stay tuned and please pass me any info related to HOT and Managed Lane modeling with simulation.