Travel Demand Modeling is used in various aspects of transportation planning such as Regional Transportation Plans, Air Quality Conformity requirements, Corridor Analyses and other regional transportation programs involving policy decisions. The Four-Step process has provided the basis for most travel forecasts performed by Metropolitan Planning Organizations (MPO) across the nation. The Four-Step process involves Trip Generation, Trip Distribution, Mode Choice and Traffic Assignment procedures. While this process has been mostly efficient in predicting travel demand for traditional highway facilities, its' ability to predict demand for toll facilities and Managed Lanes (HOV Lanes, HOT Lanes and Express Toll Lanes) has been under scrutiny. Such facilities have become more common over the last fifteen years and are increasingly planned in major cities.
Baez Consulting, under contract with URS and the Baltimore Metropolitan Planning Council (BMC), researched the state-of-the-practice strategies for doing travel demand modeling for Managed Lanes and recommended the most practical approach procedure to be incorporated into the BMC regional travel demand model