A Comparative Safety Analysis of Bicycle Infrastructure Treatments at Intersections

Bicycles offer a tangible solution to the congestion, pollution, and accessibility issues that transportation systems face today. Unfortunately, more than a century of automobile dominated design has prioritized automobiles over all other modes, creating at times, a challenging roadway environment for bicyclists. In an effort to promote bicycling, cities have been investing in the design and implementation of bicycle-specific infrastructure. However, due to their relatively recent introduction and overall lack of bicycle data, it is often a challenge to effectively evaluate the many rapidly evolving bicycle infrastructure designs. This paper utilizes a framework for expanding upon limited data to make a comparative bicycle safety analysis of bicycle infrastructure treatments. This study compares intersections with bike-boxes, bicycle through lanes, green painted bicycle through lanes, sharrows, and without treatments in the City of Cambridge, Massachusetts. The safety improvement from bike lanes is 17% when considering bicycle volume alone, and 30% when considering a combined volume of bicycles and automobiles. However, the statistical significance of this is weak, only achieving 86% and 93% confidence for the bicycle exposure alone and the combined exposure rates, respectively. Despite the limited data, the methodological approach employed herein overcomes the common challenges and limitations that bicycle safety analyses face, providing a useful tool for future studies.

• Supplemental Notes:
  • This paper was sponsored by TRB committee ANF20 Standing Committee on Bicycle Transportation.
• Authors:
  • Fournier, Nicholas
  • Deliali, Aikaterini
  • Christofa, Eleni
  • Knodler, Michael A
• Conference:
  • Transportation Research Board 97th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2018-1-7 to 2018-1-11
• Date: 2018

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; Maps; References; Tables;
• Pagination: 7p

Subject/Index Terms

• TRT Terms: Alternatives analysis; Bicycle facilities; Bicycles; Bicycling; Intersections; Safety
• Geographic Terms: Cambridge (Massachusetts)
• Subject Areas: Operations and Traffic Management; Pedestrians and Bicyclists; Planning and Forecasting; Safety and Human Factors; Terminals and Facilities;

Filing Info

• Accession Number: 01658478
• Record Type: Publication
• Report/Paper Numbers: 18-05896
• Files: TRIS, TRB, ATRI
• Created Date: Jan 31 2018 10:37AM