Citation

Hanscom FR. Transp. Res. Rec. 1975; 531: 18-35.

Copyright

(Copyright © 1975, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

This field study examined driver responses to a potentially slippery bridge during periods of possible preferential icing. Study objectives were to examine motorists' general awareness of the hazard and to assess the relative effectiveness of various warning sign treatments. Measures of signing effectiveness were motorists' speeds at critical bridge approach locations and questionnaire response regarding motorists' observations and interpretations of the signs. Two bridge approaches were signed with combinations of activated and nonactivated signs at the bridge and 1,000 ft (305 m) before the bridge during periods of possible preferntial icing. Significant speed reductions on the bridge and at the bridge entry were elicited by activated signing. The most effective signs were (a) activated, before the bridge, and (b) activated, at the bridge during hours of darkness. Activated signing used at the bridge was observed to have a greater impact than activated signing used before the bridge. Drivers were more responsibe to the signs during hazardous periods. Bridge-approach roadway geometry was seen to affect motorists' observation of and response to the signing. Improved results were obtained on a short sight-distance approach where the bridge did not visually compete for driver attention.