Dedicated Curbside/Offset Bus Lanes

Application

Dedicated bus lanes are typically applied on major routes with frequent headways (10 minutes at peak) or where traffic congestion may significantly affect reliability. As on-time performance degrades, consider more aggressive treatments to speed transit service. Agencies may set ridership or service standard benchmarks for transitioning bus service to a transit only facility.¹ Lanes may be located immediately at the curb or in an offset configuration, replacing the rightmost travel lane on a street where parking is permitted.

Benefits & Considerations

Bus lanes reduce delays due to traffic congestion and help raise the visibility of the high-quality service.

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Curbside and offset bus lanes are subject to encroachment due to double-parking, deliveries, or taxicabs. Strict enforcement is necessary to maintain their use and integrity.²

Critical

1BUS-ONLY pavement markings should be applied to emphasize the lane and to deter drivers from using it (MUTCD 3D-01).

2Dedicated lanes should be separated from other traffic using solid single or double white stripes.

Recommended

Bus lane width should be determined based on the available street space and the competing needs of bicyclists, pedestrians, and motorists. The minimum width of a curbside bus lane is 11 feet. The minimum width of an offset bus lane is 10 feet.

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3Bus bulbs should be installed if lanes are offset. Bus lanes may have complementary effects with other bus rapid transit elements, such as off-board fare payment and transit signal priority.

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Transit signal priority should be implemented wherever feasible to reduce transit delays due to traffic signals. Shorter signal cycles also process movements more efficiently and maximize the usefulness of the transit signal priority system.

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Red colored paint should be applied to emphasize the lane and to deter drivers from using it. Red paint has higher installation and maintenance costs, but has been shown to deter both unauthorized driving and parking in the bus lane.³

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Prohibiting right turns during hours when the dedicated lane is in effect or otherwise separating these movements helps to keep the lane clear.

Optional

Bus lanes may be separated with soft barriers (i.e., rumble strips) or hard barriers (concrete curbs). If hard separation is used, bus lanes should be designed to allow passing at selected points.

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Dedicated bus lanes may be implemented on a 24-hour basis or managed for specific intervals of the day only.

1. King County Metro is implementing bus-only lanes on a portion of Route 120, one of its top 10 busiest routes, with 7,000 daily boardings.
   
   “Improving Route 120,” Metro Transit, accessed May 30, 2013. http://metro.kingcounty.gov/have-a-say/projects/route120/.
   
   VTA in Vallejo, CA adopted service design guidelines with metrics such as boardings per revenue hour to transition local bus to BRT.
   
   Bus Rapid Transit Service Design Guidelines (San Jose: Santa Clara Valley Transportation Authority, 2007). ↩︎
2. The New York City Department of Transportation, in partnership with New York City Transit (NYCT), the Metropolitan Transportation Authority, and City Council members, successfully lobbied the state for legislation allowing installation of bus lane enforcement cameras as part of the new Select Bus Service (SBS), which has red-painted bus-only lanes. The SBS system uses two types of cameras. Fixed video cameras were installed on two routes beginning in November 2010. NYC DOT watches the footage and reports violations. Currently, NYCT is piloting cameras mounted on buses that take photos. Since SBS vehicles run on very short headways of 3–4 minutes, if a vehicle shows up on the two consecutive vehicles’ cameras, a violation is recorded. ↩︎
3. William Carry et al., “Red Bus Lane Treatment Evaluation,” Institute for Transportation Engineers (Washington, D.C.: 2012). ↩︎