TEI helped METRO understand and evaluate the impacts to local bus operations of geometric changes proposed in the City of Houston Lower Westheimer Corridor Study. Lower Westheimer hosts METRO’s 82 Westheimer, the busiest bus line in Texas. The Corridor Study proposed:
- Narrowing much of the corridor from a four-lane cross-section to two lanes, in order to improve safety, increase walkability, and foster economic development.
- Locating bus stops in bus pull-outs, removing stopped buses from the travel lane but potentially introducing delay to the buses when reentering traffic.
TEI developed a microscopic traffic simulation of the corridor which considered traffic signal timing, turning movement counts, traffic volumes, and assumed a traffic growth rate for the design year. TEI calibrated the model using GPS-based bus travel time runs and ridership data. The model was used to assess five design scenarios which varied bus and traffic signal operations. TEI evaluated traffic reentry delay for buses stopping at each stop along the corridor in each configuration.
Based on the findings, TEI developed recommendations for minor revisions to the schematic to ensure reliable bus travel times, which were accepted by the City. With these revisions and inclusion of transit signal priority (TSP) at minor intersections, the simulation results indicated that buses would traverse the corridor slightly faster, on average, than they do today despite the narrower cross-section.
METRO conducted field tests of the bus stop geometry at a bus operating facility to help refine recommendations for specific dimensions to provide visibility for safe and smooth operation. TEI also provided guidelines for when and how to consider bus pull-outs, and strategies for reducing stop dwell time.