Rail crossings

Rail crossings through or near a roundabout may involve many of the same design challenges as at other intersections and should be avoided if better alternatives exist. In retrofit, the rail track may be designed to pass through the central island, or across one of the legs. Queues spilling back from a rail blockage into the roundabout can fill the circulatory roadway and temporarily prevent movement on any approach. However, to the extent that a roundabout approach capacity exceeds that of a signal at the same location, queues will dissipate faster. Therefore, a case specific capacity and safety analysis is recommended. Section 8.2 addresses the design of at-grade rail crossings.