Portland’s boarding bulb program, originally developed to improve pedestrian and bicycling operation, has also yielded benefits to transit operations. The installation of enhanced boarding space on NW 23rd Avenue by the City of Portland and TriMet, the region’s transit agency, shows how this treatment confers benefits across modes and activates on neighborhood main streets.
NW 23rd Avenue, the first street in Portland where boarding bulbs were implemented, is a main street in the Nob Hill neighborhood. The mile-long corridor has a strong mix of residential, retail, and recreational destinations, in an actively used 60-foot right-of-way. This neighborhood main street serves a frequent bus line with roughly 10-minute headways, and draws substantial bicycling, walking, and driving volumes, with one lane in each direction, parallel parking on both sides, and tree-lined 12-foot sidewalks. The Portland streetcar serves the northern portion of the corridor.
Providing both multi-modal capacity and safe, transit-friendly traffic speeds were key project goals. The city installed bus bulbs at each of the transit stops along NW 23rd Avenue, expanding the pedestrian space and allowing transit vehicles to make in-lane stops. The shared bus-streetcar stops also feature a dual-height curb profile, with a rear streetcar-level section (14 inches high) and a front bus section (6 inches high), allowing both vehicles to offer accessible boardings from the same platform. Additionally, stops were consolidated to a 750-foot (three-block) spacing, allowing higher boarding volumes at fewer stops, along with the addition of shelters and green infrastructure.
In-lane stops have had a variety of benefits. Prior to the project, transit operators noted that buses rarely pulled out of traffic to reach the existing sidewalk stops, either due to difficult turning maneuvers or vehicles blocking the bus zone. Since implementation, motor vehicle travel times and traffic speeds have remained unchanged, while the percentage of cars speeding has declined.
Satisfaction with the stop enhancements is high; transit operators report easier loading, especially for riders using wheelchairs, and pedestrians have improved perceptions of traffic stress and walking comfort.