The California Vehicle Code allows drivers to turn right on red after coming to a complete stop, unless prohibited by a sign. Right turn on red (RTOR) prohibitions can be an important tool for increasing pedestrian safety at certain intersections. Under some circumstances, prohibiting RTOR can reduce conflicts and collisions, and it deters motorists from blocking the perpendicular crosswalk while they inch forward to turn. On the other hand, prohibiting RTOR may mean increased vehicle delay, including delay to transit. RTOR prohibition can also lead to more conflicts during right turns on green, since turning motorists must now wait to turn while pedestrians are crossing with the green light.
The MUTCD and the Institute of Transportation Engineers suggest considering the prohibition of RTOR under the following circumstances:
- inadequate sight distance to vehicles approaching from the left (or right, if applicable);
- geometrics or operational characteristics of the intersection that might result in unexpected conflicts;
- an exclusive pedestrian phase;
- an unacceptable number of pedestrian conflicts with right-turn-on-red maneuvers;
- heavy volume of pedestrian crossings;
- request from pedestrians with disabilities using the intersection;
- school crossings;
- railroad crossings; and
- traffic signals with three or more phases.
Beyond the conditions listed above, the City also considers high speeds on cross streets and a verified collision history caused by RTOR maneuvers. As of 2007, signs were posted on one or more approaches of 14% of all signalized intersections citywide (169 out of 1,166).
San Francisco’s practice of considering RTOR prohibition at intersections on a case-by-case basis should be continued, subject to the guidelines listed above. RTOR prohibitions may be considered at intersections that:
- have fewer than 300 cars making the right turn per hour; and
- do not have curb-running transit with near-side transit stops.
At intersections that do not meet all of these criteria, RTOR prohibitions may still be appropriate pursuant to additional study and environmental review.
Multiple turn lanes
Compared to single turn lanes, multiple turn lanes decrease pedestrian comfort and increase potential conflicts between turning vehicles and pedestrians crossing concurrently with the vehicular turning movement. Safety may be compromised if one turning vehicle obscures the driver’s view of pedestrians in the crosswalk from a second, trailing vehicle in an adjacent turn lane. Multiple turn lanes may also compromise bicycle safety.
The presence or absence of multiple turn lanes is not by itself a predictor of an intersection’s propensity to generate pedestrian collisions. It is important to consider how removing a multiple turn lane and requiring the same number of vehicles to turn from one lane will affect pedestrian and vehicular safety. However, pedestrian perception of safety and conflict reduction is also an important consideration in intersection design. Multiple turn lanes should be avoided wherever possible. No new multiple turn lanes with conflicting vehicle/pedestrian movements should be built in San Francisco. Existing multiple turn lanes should be pro-actively eliminated or mitigated.
Feasibility of multiple turn lane removal is contingent upon vehicle level of service, queuing, transit operations, and upstream traffic safety considerations. Even if consideration of these criteria do not point to removal of multiple turn lanes, it may still be advisable to make lane assignment changes if there is a documented history of relevant collisions involving pedestrians, and other attempted mitigations have proven ineffective.
If removal is not possible, the City should consider potential mitigations for multiple turn lane conditions found to be problematic. Strategies to mitigate problematic multiple turn lane conditions include the following:
- separate pedestrian and turning movements;
- leading pedestrian intervals;
- permissive-protected signal phasing (pedestrian crossing phase ends before vehicle phase);
- limited hours of multiple turn lanes;
- parking restrictions; and
- signs and enforcement.