Pedestrian Safety Guide and Countermeasure Selection System


Bus bulbs provide space for stop amenities and bus patrons to board and alight while allowing pedestrians to pass through unobstructed. Photo by Michael Hintze




Bus Bulb Outs

Bus bulbs allow buses to stop in-lane thereby eliminating the need to re-enter the traffic flow. This increases bus reliability since the bus driver no longer needs to wait for a gap in traffic; and it increases safety by reducing the potential for conflict when entering the traffic flow. Additionally, where it is not possible to provide a pad or sidewalk of sufficient width for accommodating waiting passengers and passing pedestrians, bus bulb outs (i.e. elongated curb extensions) can provide additional space for passengers to board and alight transit vehicles without interfering with sidewalk flow. The bulb out should be long enough to allow passengers to board and alight at all doors of the bus. Bus bulb outs can also have positive traffic calming effects by narrowing the roadway, and when placed at intersections, can be designed with smaller curb radii that force right-turning vehicles to reduce speed. When coupled with a pedestrian crossing, bus bulb outs, like curb extensions, also reduce pedestrian exposure by shortening the crossing distance. Bulb outs also make pedestrians who are about to enter the crosswalk more visible to approaching traffic by putting them out beyond objects like parked cars or street trees, which may obstruct driver visibility.


Provide additional space at transit stops for waiting patrons and passing pedestrians while also allowing buses to stop in lane, thereby increasing bus reliability and safety.


• The width of the bulb out should generally be 6 to 7 feet, but should not be wider than the adjacent parking lane.
• When placed at intersections, design bulb outs with smaller curb radii to slow turning vehicles.
• Use additional space provided by bulb out to provide enhanced stop lighting, seating and other bus stop and streetscape features.
• Incorporate curb ramps into bulb out when placed at intersections.
• While bus bulbs can improve transit operations because buses stop in the travel lane rather than pulling over to the curb, they may negatively impact motor vehicle traffic flow, especially on two-lane arterials.

Estimated Cost

Costs for constructing bus bulbs can range between $15,000 and $70,000 per bulb, and depend upon drainage needs, utility relocation, construction materials, and patron amenities.

Case Studies

Englewood, Ohio
San Francisco, California