Title

PRESIGNALS: CURRENT APPLICATIONS AND ISSUES

Authors

B D. Ogden

Document Type

Journal Article

Publication Date

2001

Subject Area

planning - safety/accidents, mode - rail, mode - tram/light rail

Keywords

Transit safety, Road safety, Regulatory policy, Railroad grade crossings, Presignals, Policy, Policies, Light rail transit grade crossings, Light rail transit, Level crossings, Highway safety, Highway railroad grade crossings, Highway rail intersections, Grade crossings, Grade crossing signals, Grade crossing protection systems, Government policy, Active grade crossing warning systems

Abstract

Applications and technical issues related to using presignals to improve the safety of at-grade light rail transit crossings are discussed. A presignal installation has roadway traffic signal heads placed ahead of a downstream, signalized frontage roadway intersection and the stop bar displaced in advance of the grade crossing. This signal ensures that a vehicle stops at a red traffic light before the grade crossing area and the clear-storage zone between the grade crossing and downstream intersection. Presignals have been used for many years and are a state standard in Michigan and South Carolina. However, a tragic accident in which a school bus was hit by a METRA commuter train in Fox River Grove, Illinois, brought renewed attention to this treatment. The state of Illinois installed a presignal at the Fox River Grove grade crossing and has developed a statewide policy for the use of presignals elsewhere. Background is provided on presignals, including alternative types of queue control using traffic signals. The key design features of a presignal installation are highlighted. Outstanding technical issues are identified, including future research to refine policies or warrants for presignals and applicable design standards.