More Than Sharrows: Lane-Within-a-Lane Bicycle Priority Treatments in Three U.S. Cities

When a street is too narrow to have exclusive bike lanes, cars and bikes have to share a lane. Without a clear bicyclist zone being designated, bicyclists and motorists have to negotiate for the boundary of the bicycle zone. The dynamics of this negotiation and the stresses it engenders are analyzed. Existing treatments to encourage intended motorist and bicyclist behavior in shared lanes are analyzed, including the increasingly popular “sharrow” and Dutch suggestion lanes or advisory lanes. Criteria for an effective shared-lane treatment are developed. A critical feature is longitudinal markings that delineate a bicycle zone as a lane-within-a-lane, a treatment called a Bicycle Priority Lane. Salt Lake City and Long Beach (CA) have each applied this treatment on a 4-lane road using green carpet color to indicate the priority zone, while Brookline (MA) has recently applied it on a 2-lane road using dotted white lines to indicate the priority zone. Before-after studies show that priority lane treatments have some success in shifting cyclists’ position further away from parked cars and curbs and away from using the sidewalk. However, the substantial fraction of cyclists continuing to ride on the sidewalk or in the door zone suggests that the prevailing paradigm in the U.S. of bicycles never blocking automobiles is difficult to overcome.

• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Furth, Peter G
  • Dulaski, Daniel M
• Conference:
  • Transportation Research Board 90th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2011-1-23 to 2011-1-27
• Date: 2011

Language

• English

Media Info

• Media Type: DVD
• Features: Figures; References; Tables;
• Pagination: 22p
• Monograph Title: TRB 90th Annual Meeting Compendium of Papers DVD

Subject/Index Terms

• TRT Terms: Bicycle facilities; Bicycle lanes; Bicycling; Cyclists; Green; Lane lines; Passing; Safety; Traffic conflicts; Vehicle mix
• Uncontrolled Terms: Sharrows
• Geographic Terms: Brookline (Massachusetts); Long Beach (California); Salt Lake City (Utah)
• Subject Areas: Operations and Traffic Management; Pedestrians and Bicyclists; Safety and Human Factors; I73: Traffic Control; I82: Accidents and Transport Infrastructure;

Filing Info

• Accession Number: 01337947
• Record Type: Publication
• Report/Paper Numbers: 11-1357
• Files: TRIS, TRB
• Created Date: Apr 27 2011 7:21AM