Measures for Preventing Wrong-Way Entries on Highways

About the report:

An evaluation of the results of a two-year survey of incidents of wrong-way driving on Virginia highways revealed that the majority of them originated at diamond type interchanges. On-site investigations of a number of the interchanges at which instances of wrong-way driving had been noted suggested several improvements. The report discusses measures for preventing wrong-way entries at interchanges and presents case studies of four of the interchanges visited. Some of the recommendations are given below: (1) Channelize the left lane of the exit ramp and remove the left end flare, preferably by providing a corner barrier. The corner barrier will prevent the use of shoulders for a wrong-way turn. (2) Properly locate signs based on the size of letters or symbols in the message and the cone of vision. (3) Provide intersection geometry information to the drivers entering a four-lane divided highway in the form of an information geometry sign. (4) As an aid to mentally impaired drivers, provide supplemental signs with pavement markings and spotlighting to make entry ramps conspicuous and exit ramps inconspicuous. Specific techniques like the provision of double yellow lines without full openings, continuation of pavement edge lines across exit ramps, and bringing stop lines closer to pavement edge lines seem to pay off and are recommended for further evaluation.

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