Bicycle Safety Guide and Countermeasure Selection System


Source: Manual on Uniform Traffic Control Devices




Turning Restrictions

A frequent crash type involves a collision between a bicycle and a turning motor vehicle. One scenario involves a bicyclist going straight ahead and an oncoming motorist turning left at an intersection or into a driveway. If the motorist is intent on finding a gap between oncoming motor vehicles, he or she may fail to recognize an approaching bicyclist. Another scenario involves motor vehicles turning right on red.

A permissible Right Turn on Red (RTOR) was introduced in the 1970s as a fuel-saving measure and has sometimes had detrimental effects on bicycling. While the law requires motorists to come to a full stop and yield to cross-street traffic, including bicyclists (and pedestrians), before turning right on red, many motorists do not fully comply with the regulations, especially at intersections with wide turning radii. In addition, motorists are so intent in looking for traffic approaching on their left that they may not be alert to bicyclists (or pedestrians) approaching on their right. Motorists also often pull into the crosswalk area to wait for a gap in traffic, which may put them directly in the path of bicyclists (or pedestrians) crossing in the crosswalk.

Prohibiting RTOR should be considered where there are high bicycle (or pedestrian) volumes and conflicts with right-turning vehicles. The standard regulatory sign included in the MUTCD states NO TURN ON RED, but alternative sign options include a circular red icon or a larger 30-in by 36-in NO TURN ON RED sign, both of which improve conspicuity. For areas where a right-turn-on-red restriction is needed during certain times, time-of-day restrictions may be appropriate. A variable-message NO TURN ON RED sign is also an option. RTOR restrictions should also be used in conjunction with a bike box or advanced stop line.

A partial restriction may prohibit left turns except for bicycles and transit. Such signs could be used in conjunction with bicycle boulevards or other low-volume, low-speed streets to not only reduce conflicts at the intersection, but help create a preferential bicycling cross-street. Turns may also be restricted with diverters and partial diverters.


Turning restrictions can increase bicycle (and pedestrian) safety and decrease crashes with turning motor vehicles. This also increases safety in crosswalks.


  • Signs should be checked to assure adequate nighttime reflectivity.
  • Part-time RTOR prohibitions during the busiest times of the day may be sufficient to address the problem.
  • Signs should be clearly visible to right-turning motorists stopped in the curb lane at the crosswalk.
  • RTOR restrictions are used at every intersection with crossing guards or with inadequate sight distances.
  • RTOR restrictions should be used at school crossings.

Estimated Cost

Sign costs are variable but typically range from $30 to $150. Installation may cost another $200. Electronic signs are appreciably more expensive.


To view references for this countermeasure group click here.

Case Studies

Palo Alto, California