Commonway
Version V. 2026.09.03

Transit priority lane retrofit

RFT-CDR-06 Corridor

Transit priority lane retrofit

Converts an existing general travel lane or on-street parking lane into a lane dedicated to bus travel, curbside or center-running.

#Overview

On a bus route with frequent service and heavy congestion, buses stuck in general traffic lose the reliability advantage that makes transit competitive with driving. Dedicating a lane to buses, marked with red paint and "Bus Only" signage in most U.S. applications, removes that conflict. The lane can run curbside, offset from the curb to preserve a parking or loading lane, or along the center median on a wider corridor.2

#Where this leads: Target patterns

Local Transit (LOC-LTR-10), Collector Transit (COL-CTR-05), Arterial Transit (BRT/LRT) (ART-ATR-04)

#Applicability and thresholds

Most applicable on corridors with frequent bus service experiencing measurable delay from mixed traffic, particularly where curb, street, or driveway conflicts are low to moderate; where conflicts are high, a curbside lane may need to shift further from the curb or run center-median instead.

#Evidence and effectiveness

Agencies implementing dedicated and business-access-and-transit lanes report improved bus speed and schedule reliability, with the effect scaling with how much of the corridor's delay was previously caused by mixed-traffic conflict rather than signal timing or stop dwell time.13

#Getting it built

Frequently piloted with temporary cones, signage, and paint before permanent installation, since testing the lane's effect on both bus reliability and general traffic before committing to red paint and enforcement infrastructure is common practice. See Construction Methodology & The Build Spectrum.

#Who can move this

Typically a joint decision between the transit agency and the city or county transportation department, since the lane affects both bus operations and general traffic capacity. See Legal & Planning Mechanisms.

Parking-lane reallocation (RFT-CDR-05) (the underlying mechanism when the transit lane replaces parking rather than a travel lane)

#References

  1. Precedent-based Nelson\Nygaard, "Better Bus Transit Priority Toolkit," prepared for TriMet, March 2024.
  2. Precedent-based NACTO Urban Street Design Guide, "Transit Corridor," Transit Streets section.
  3. Evidence-based Federal Transit Administration, "Bus Lanes."

Suggest changes to this page (opens in new tab) Last updated September 3, 2026