Evaluation of Shared Lane Markings in Cambridge, Massachusetts

Shared lane markings (sharrows) convey the message that motorists and cyclists must share the travel way on which they are operating. The purpose of the markings is to create improved conditions for bicycling by clarifying where cyclists are expected to ride and reminding motorists to expect cyclists on the road. A before–after evaluation was conducted to compare how cyclists and motorists operated on a street with parallel parking in Cambridge, Massachusetts, with no markings versus with sharrows placed 10 ft (3.05 m) from the curb. This evaluation, which was part of a broader FHWA study on sharrows, was intended to help determine whether an alternative to the 11-ft (3.4-m) spacing recommended in the 2009 version of the Manual on Uniform Traffic Control Devices would be effective. Operational and safety measures for bicyclists and motorists were examined. Overall, safety effects appeared to be associated with the installation of the sharrows placed 10 ft (3.05 m) from the curb. Perhaps the most important effect was the 14-in. (36-cm) increase in spacing between motor vehicles in the travel lane and parked motor vehicles when no bicycles were present. This effect increased the operating space for bicyclists. Many variables related to the interaction of bicycles and motor vehicles also showed positive operational and safety effects.

• Record URL:
  https://doi.org/10.3141/2247-09
• Summary URL:
  http://scholar.google.com/scholar_lookup?title=Evaluation+of+Shared+Lane+Markings+in+Cambridge%2c+Massachusetts&author=W.+Hunter&author=R.+Srinivasan&author=L.+Thomas&author=C.+Martell&author=C.+Seiderman&publication_year=2011
• Availability:
  • Find a library where document is available. Order URL: http://www.trb.org/Main/Blurbs/166530.aspx
• Authors:
  • Hunter, William W
  • Srinivasan, Raghavan
  • Thomas, Libby
  • Martell, Carol A
  • Seiderman, Cara B
• Publication Date: 2011

Language

• English

Media Info

• Media Type: Print
• Features: Figures; Maps; Photos; References; Tables;
• Pagination: pp 72-80
• Monograph Title: Bicycles 2011
• Serial:
  • Transportation Research Record: Journal of the Transportation Research Board
  • Issue Number: 2247
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Before and after studies; Cyclists; Drivers; Highway design; Highway operations; Highway safety; Lane lines; Road markings; Traffic lanes; Traffic safety
• Uncontrolled Terms: Shared-use lanes; Sharrows
• Geographic Terms: Cambridge (Massachusetts)
• Subject Areas: Highways; Operations and Traffic Management; Pedestrians and Bicyclists; Safety and Human Factors; I73: Traffic Control; I82: Accidents and Transport Infrastructure;

Filing Info

• Accession Number: 01333243
• Record Type: Publication
• ISBN: 9780309167673
• Report/Paper Numbers: 11-1467
• Files: PRP, TRIS, TRB, ATRI
• Created Date: Mar 21 2011 2:13PM