Document Type

Journal Article

Publication Date


Subject Area

operations - traffic, infrastructure - stop, infrastructure - vehicle, infrastructure - bus/tram lane, infrastructure - bus/tram lane, place - urban, mode - bus, mode - pedestrian


Urban areas, Transit vehicle operations, Transit Cooperative Research Program, Transit authorities, Traffic mitigation, Stop (Public transportation), Road transportation, Road engineering, Pedestrian movement, Motor bus transportation, Mitigation measures, Intracity bus transportation, Intercity bus transportation, Highway transportation, Highway engineering, Crossing The Road, Bus transportation, Bus transit operations, Bus transit, Bus stops, Bus stop shelters, Bus lanes, Bus bulbs


Bus bulbs, also called nubs, curb extensions, or bus bulges, are sections of sidewalk extending from the curb of a parking lane to the edge of the through lane. In regard to traffic operations, bus bulbs operate similar to curbside bus stops. Buses stop in the traffic lane instead of weaving into a parking-lane curbside stop. A major advantage of using bus bulbs is the creation of additional space at a bus stop for bus-patron improvements (shelters, benches) when the inclusion of these amenities would otherwise be limited without the additional space. This article presents guidelines for bus bulbs developed as part of a recent Transit Cooperative Research Program project. In this project, transit agencies were surveyed to determine best practices being applied during bus-stop design and location decisions. Findings from this survey are also provided and discussed, including information on how bus bulb configurations may change traffic and pedestrian movements and bus operations at specific locations.