The Uptown Houston District constructed dedicated bus lanes along Post Oak Boulevard to support new bus rapid transit (BRT) service, which METRO operates as the Silver Line. BRT interacts with several of the most complex traffic signal phasing and sequencing operations in the city.
TEI supported METRO with a detailed traffic and transit analysis of proposed BRT operations which:
- Developed and calibrated microscopic traffic simulation models to replicate existing traffic and signal operations;
- Evaluated BRT travel times accounting for traffic signal timing, boarding & alighting demands, and roadway geometrics; and
- Simulated and evaluated effects of transit signal priority, transit preemption, and geometric designs on BRT buses and other users (i.e. general traffic) at intersections along the corridor.
Inputs to the model included:
- Schematics of the proposed bus route, dedicated busway lanes, and stations;
- Proposed peak headway and estimated boardings and alightings;
- Existing traffic signal timings and turning movement counts at the studied intersections; and
- GPS-based travel time runs (five in each direction) during the PM peak for baseline model calibration.
Outputs of the model included details of running time, signal delay, and average speed for each segment of the corridor. Visualization of corridor operations helped decision-makers to understand the influence of signal timing on overall corridor travel time, and advanced discussions on proposed transit signal priority.Confidence in corridor travel times also allowed METRO to determine the optimal number of BRT vehicles to purchase, using capital funds efficiently.