Right Turn Lanes. Exclusive right turn lanes are less critical in terms of safety than
left turn lanes. However, right turn lanes can significantly improve the level of service
of signalized intersections. They also provide a means of safe deceleration for rightturning
traffic on high-speed facilities and separate right-turning traffic from the rest
of the traffic stream at stop-controlled or signalized intersections. As a general guideline,
an exclusive right turn lane should be considered when the right turn volume exceeds
300 vehicles per hour per lane.
Figure 2.36c shows the design of right turn lanes. Table 2.27 may be used in preliminary
design to estimate the storage required at signalized intersections. The recommended
maximum length of right turn lanes at signalized intersections is 800 ft (244 m),
with 100 ft (30 m) the minimum length.
The blockage of the right turn lane by the through vehicles should also be checked
using Table 2.27. With right-turn-on-red operation, it is imperative that access to the
right turn lane be provided to achieve full utilization of the benefits of this type of
operation.
The width of right turn lanes should desirably be equal to the normal through lane
width for the facility. In low-speed areas, a minimum width of 10 ft (3.0 m) may be
provided. Additional lane width should be provided when the right turn lane is adjacent
to a curb.