Is there a spillover effect of a right turn on red permission for bicyclists?

Abstract

Some countries allow bicyclists to perform a right turn on red (RTOR) at a number of signalized intersections to promote cycling by reducing the required physical effort and trip time. Imple-mentation of this law could lead to both local and supralocal effects on road safety. Using an experimental survey approach, this study explores whether a so-called ‘spillover effect’ of the measure can be expected. This effect implies that allowing bicyclists to turn right on red at some places causes bicyclists to also turn right on red more often at places where this is not al-lowed. The answers from 768 respondents indicate that respondents with a high awareness of the ex-istence of a RTOR rule for bicyclists turn right on red significantly more often at locations where this is not allowed than respondents with a low awareness of the rule. This indicates that implementation of the RTOR rule for bicyclists can lead to a substantial spillover effect, i.e. an increase in red light running at other locations. This might lead to safety issues at locations where no RTOR for bicyclists is allowed, since road authorities could have decided not to allow RTOR for bicyclists at these locations for safety reasons.