Citation

Foxen G. ITE J. 1986; 56(6): 48-49.

Copyright

(Copyright © 1986, Institute of Transportation Engineers)

DOI

unavailable

PMID

unavailable

Abstract

A trap lane is a through traffic lane which terminates in an unshadowed mandatory left- or right-turn regulation. This article identifies certain features which would enhance the operation of urban arterial trap lanes and warrant further consideration and more widespread application. These features include a sign giving prominent advance notice of the unexpected mandatory turn requirement, followed by a regulatory sign at the point where the mandatory turn regulation takes effect and another at the intersection itself if there are intervening driveways from which motorists might enter the lane. Supplemental pavement markings consisting of a double width broken lane line beginning at the advance warning sign and extending to the first regulatory sign should be provided, in combination with a pavement legend in the trap lane. Another possible improvement is overhead signs. Prime candidates for these include left-turn trap lanes on roads with high volumes, high speeds, poor approach visibility, and complex geometrics.