THE RELATIVE (IN)EFFECTIVENESS OF BICYCLE SHARROWS ON RIDERSHIP AND SAFETY OUTCOMES

THE RELATIVE (IN)EFFECTIVENESS OF BICYCLE SHARROWS ON RIDERSHIP AND SAFETY OUTCOMES

Nicholas N. Ferenchak, Corresponding Author
University of Colorado Denver, Civil Engineering Department

Wesley E. Marshall, PhD, PE
University of Colorado Denver, Civil Engineering Department

This work raises concerns about the effectiveness of sharrows and highlights the 18 importance of providing adequate infrastructure for bicyclists.

The exact operational function of these markings is somewhat nebulous and seems to have evolved over time. When originally conceived, the hope was that sharrows would create distance between bicyclists and parked cars in order to avoid dooring crashes. Thus, many of the early studies of sharrows designate this avoidance of dooring as a primary objective. Similarly, the initial objective listed in the MUTCD is to assist bicyclists with lateral positioning so to avoid dooring crashes. However, this dooring objective is no longer the primary aim in some cases, evidenced by the fact that sharrows are now commonly placed on streets without on-street parking.