In an attempt to evaluate the effectiveness of various safety improvements on approximately five miles of I 75 in northern Kentucky, a before-and-after analysis of accidents was conducted. Safety improvements were: 1) a variable message signing system in the northbound direction; 2) a New Jersey-type median barrier wall; and 3) general improvements such as guardrail end treatments, break-away sign installations, contour grading, etc.

Results indicate the safety improvements were effective in reducing the overall accident rate. Separate analysis also revealed that variable message signs were effective in bringing about a significant reduction in accident rates. There were no fatalities during either of the data collection periods. However, accident severity increased after the improvements. Results were influenced by low skid resistance, continued wear in wheel tracks, and increasing congestion throughout the study section.

Report Date


Report Number

No. 344

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The contents of this report reflect the views of the authors who are responsible for the facts and the accuracy of the data presented herein. The contents do not reflect the official views or policies of the Kentucky Bureau of Highways, This report does not constitute a standard, specification, or regulation.