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

• RTOR for bicyclists allowed in some countries at some specific intersections.
• Safety effects of this rule have not been studied in scientific literature before.
• Experimental survey, completed by 768 respondents.
• Respondents with higher awareness of rule: also more non-permitted RTOR.
• This indicates that the rule could lead to an unwanted spillover effect.

A number of countries allow bicyclists to perform a right turn on red (RTOR) at some specific intersections to promote cycling by reducing the required physical effort and trip time. Implementation of a rule that allows a RTOR for bicyclists at some intersections could lead not only to local effects at those intersections where the rule actually applies, but also to supralocal effects. Using an experimental survey approach, this study explores whether a so-called ‘spillover effect’ of the rule can be expected. This effect would imply that allowing bicyclists to turn right on red at some intersections causes them to also turn right on red more often at intersections where RTOR for bicyclists is not allowed.The answers from 768 respondents indicate that respondents with a high awareness of the existence of a RTOR rule for bicyclists (experimental group) turn right on red significantly more often at intersections where RTOR for bicyclists is not permitted than respondents with a low awareness of the rule (control group). This indicates that implementation of the RTOR rule for bicyclists can indeed lead to an increase in red light running at other intersections. This might lead to safety issues at intersections where RTOR for bicyclists is not permitted, since road authorities could have decided not to allow RTOR for bicyclists at these intersections for safety reasons.The study also finds that men, young people and people who generally perform more risky cycling behaviours have a higher tendency to perform non-permitted RTOR. These findings are in line with existing literature.