Traffic signal operations near highway-rail grade crossings

This synthesis presents a review of the current practices associated with the operation of traffic signals at intersections located near highway-rail grade crossings. This topic is of special concern because of the October 1995 fatal crash of a train with a school bus that remained on the tracks while stopped for a traffic signal on the adjacent roadway. This synthesis will be of interest to state and local highway design engineers and traffic engineers, and to officials concerned with the design and operation of rail systems. It will also provide useful information for safety personnel and for further design and operations improvements for traffic signalization near highway-rail grade crossings. This synthesis is provided for information only; as with any function dealing with safety, practitioners are advised to exercise appropriate judgment, carefully support the bases of decisions, and document results for their decisions. This report of the Transportation Research Board presents information on the policies and operational characteristics of highway-rail grade crossing warning devices and details on system components, including advance warning times, train detection, and traffic signal interconnection. In addition, several advanced highway-rail grade crossing warning systems in operation are described. Information on highway traffic signal systems is presented, including traffic controller preemption system characteristics. The need for agency coordination on signal preemption is emphasized. Based on the survey of highway and rail agencies conducted for this synthesis, there appears to be a need to improve the compatibility between traffic operations at highway-rail grade crossings and traffic operations at signalized intersections in the vicinity of the crossing.