H. Zhou, J. Zhao, P.-S. Lin, P. Hsu
This paper summarized the evaluation results of a short-term and long-term safety improvement program in Florida. The short-term program, called “Drive 4 Life”, is to address the safety problem on the 22-mile segment of Interstate 4 (I-4) in Hillsborough County, Florida through education and enforcement countermeasures before the engineering program. The long-term treatment is the construction of median guardrail along the same segment of I-4 after the short-term education and enforcement program. The Empirical Bayes before-after study approach was used to evaluate the safety performance of the engineering and non-engineering programs, separately. The analysis results showed that there was a significant reduction of approximately 16.3 percent in fatal and injury crashes due to the non-engineering program; and for the engineering treatment, the same crash types were reduced by 7.62 percent in the after period. Overall, the short-term and long-term program had a positive impact on the safety and was successful in reducing the number of fatal and injury crashes on the I-4 segment. Due to long design and construction period, a short-term safety program focusing on education and enforcement should be considered to temporarily reduce the increasing traffic crashes caused by aggressive driving and speeding. This study gave a successful example of application of such a program to significantly reduce the fatal and injury crashes in both short-term and long-term.
Keywords: Empirical Bayes before-after study; “Drive 4 Life” campaign; median guardrail; safety performance