Boarding bulb width must meet accessibility requirements (ADA Std. 810.2.2). With most ramp technology, boarding areas at each accessible door must be 5 by 8 feet, along with 4-foot clear paths to reach each accessible door (ADA Std. 403.5.1) (see page 67). Shelters, seating, trash bins, plantings, vending machines, and utility boxes must be placed clear of accessible paths.
Cross-slopes no greater than 2% should be provided along the accessible paths and landing area.
Coordinate to ensure placement of accessible boarding areas is compatible across all vehicles in the transit fleet serving the stop.
At stops adjacent to crosswalks, provide at least 10 feet of clear sidewalk space, ahead of transit vehicle at near-side stops and behind the transit vehicle at far-side stops.
If shelters are placed on boarding bulbs, they must be placed clear of front- and back-door boarding areas.
Boarding bulb length is determined by the boarding area required for the expected number of buses dwelling at a given moment (see page 62), but should be at least long enough to serve all doors of at least one design vehicle.
Boarding bulb stops should include passenger features like shelters, seating, wayfinding, and route information.
At bus stops, extend the bulb to within 2 feet of the edge of the travel lane; bulbs typically extend 6–8 feet from the existing curbline, and require minimal lateral movement for bus access.
Extend the boarding bulb at far-side stops to provide room for cars to queue behind a dwelling bus. Signs and markings should communicate to drivers not to “block the box.”
Include green features like bioswales or planters to improve streetscape and stormwater recapture.
Where traffic buildup behind transit vehicles is of concern (i.e. where a street has one travel lane in each direction), periodic pull-out stops may be used to allow vehicles to pass buses. Priority treatments to allow buses to re-enter traffic should be provided.