Citation

Ward NJ, Wilde GJS. Safety Sci. 1996; 22(1-3): 63-75.

Copyright

(Copyright © 1996, Elsevier Publishing)

DOI

unavailable

PMID

unavailable

Abstract

Common sense dictates that railway crossing with restricted lateral visibility should be more hazardous than sites with unrestricted visibility (Schoppert and Hoyt, 1968). However, evidence of any relationship between lateral sight distance and accident history has not been consistently demonstrated. Based on the tenets of risk homeostasis theory, Wilde et al. (1987) explain this disassociation in terms of motorist compensatory behaviour (e.g. speed reduction) in response to the perceived risk associated with restricted visibility. This regulatory mechanism is expected to sustain a more-or-less constant safety margin. This proposition was explored in this study by examining the effect of enhancing lateral sight distances at an unprotected crossing. Parallel observations were made at an untreated site to control for secular confounding. As expected, improvement of lateral sight distances resulted in an upstream shift toward longer search durations and a tendency toward faster approach speeds, but failed to produce a calculated net safety benefit. A survey of local residents suggests that the enhancement treatment reduced perceived risk. Results are discussed with respect to the merits of sight distance enhancement and alternative interventions.