Paper Details

TRB 90th Annual Meeting (January 23-27, 2011)

Event Number:	567
Event Title:	Innovative Bicycle Infrastructure: Is It Working?
Event Date:	Jan 25 2011 3:45PM- 5:30PM
Event Location:	Marriott, Delaware A
Event Description:
Event Agenda:	1. Learn about recently developed and installed bicycle infrastructure designs/treatments 2. Learn about performance measures used to evaluate these new treatments/designs 3. Learn if these new treatments and designs are working from safety and operational perspectives

Evaluation of Shared Lane Markings in Cambridge, Massachusetts (11-1467)

Shared lane markings are intended to 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 to remind motorists to expect cyclists on the road. This paper is a before-after evaluation comparing how cyclists and motorists operated on a street with no markings versus the street with sharrows placed at a10-foot (3.05 m) spacing from the curb on a street with parallel parking in Cambridge, MA. This evaluation, which is part of a broader Federal Highway Administration study on sharrows, is intended to help determine if an alternative to the 11-foot (3.4 m) spacing recommended in the 2009 version of the Manual of Uniform Traffic Control Devices is effective. Operational and safety measures for bicyclists and motorists were examined. Overall, there appear to be safety effects associated with the installation of the sharrows when using the 10 foot (3.05 m) spacing from the curb. Perhaps the most important effect is the 14-inch (36 cm) increase in spacing between motor vehicles in the travel lane and parked motor vehicles when no bicycles are present. This would tend to increase the operating space for bicyclists. A number of variables related to the interaction of bicycles and motor vehicles also showed positive operational and safety effects.

Authors
     Hunter, William Wesley, University of North Carolina, Chapel Hill
     Srinivasan, Raghavan , University of North Carolina, Chapel Hill
     Thomas, Libby , University of North Carolina, Chapel Hill
     Martell, Carol , University of North Carolina, Chapel Hill
     Seiderman, Cara B., City of Cambridge, MA