In order to study the impact of various scenarios on traffic circulation on the Sheridan Expressway, NYCDOT commissioned STV Inc., Cambridge Systematics and Aimsun to develop and calibrate both a mesoscopic model and a hybrid model of the wider area.
The Sheridan Expressway mesoscopic model was a wide sub-area extraction from the larger area Manhattan Traffic Model (MTM) with added details and highway extensions in the Bronx. Underlying travel demand patterns and growth forecasts were extracted from the New York Best Practices Model (NYBPM) of the New York Metropolitan Transportation Council (NYMTC), the Metropolitan Planning Organization for the New York City region.
In addition to evaluating scenarios at the mesoscopic level, the team applied a hybrid modelling approach to further assess changes in traffic patterns along alternative routes, especially in the vicinity of Sheridan Expressway and the Hunts Point peninsula. This allowed the team to study certain critical locations, such as complex merge and weaving segments, in microscopic detail within a larger mesoscopic model. First, the team developed and calibrated a mesoscopic model applying Dynamic Traffic Assignment (DTA) according to the Dynamic User Equilibrium (DUE) principle. Then the modelers selected any areas that required microscopic detail and ran the hybrid model.