Left Turn Treatments at Intersections

NCHRP Synthesis 225 entitled "Left Turn Treatments at Intersections" has recently been published by TRB. The report, which is authored by James L. Pline and reviewed by a committee of ten transportation professionals, thoroughly discusses the basic concerns related to left turn movements and the guidelines and requirements for handling these movements in the traffic stream. It also addresses the design criteria for left turn treatments and performance measures frequently applied to determine their effectiveness. The synthesis also discusses the specific requirements for signing and pavement marking, and the various elements of traffic signal requirements, signal design and installation, phasing, optimization and lane use controls. There is also a description of special applications such as U-turn control, pedestrian requirements, bicycle, and transit interface. The report costs $22.00 and can be obtained from Transportation Research Board, National Research Council, 2101 Constitution Avenue, N.W. Washington, DC 20418. (Courtesy Martin Bretherton, Georgia ITE Section.)