Oluwaseun Olufowobi



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The impacts of raised speed limits on traffic safety is an area that has generated much research, although a strong consensus has not emerged on the relationship between speed and safety. In response to the nationwide ongoing trend of raising speed limits, led to the implementation of the 70-mph speed limit on 570 miles of rural freeways in Ohio on July 1, 2013 and an additional 398 miles of rural freeways starting on September 29, 2013. The primary goal of the research detailed in this study is to investigate the safety impacts of this new speed limit using available crash, roadway, and traffic characteristics data. Statewide crash data from January 1, 2010 to December 31, 2018 were obtained from the Highway Safety Information System (HSIS). The study utilizes the empirical Bayes before-after study method. The intent of this method is to estimate the actual performance (in terms of crash frequency and severity) following the speed limit Increase and what the performance would have been if the increase in speed limit had not been applied.

Publication Date


Project Designation

Graduate Research

Primary Advisor

Deogratias Eustace

Primary Advisor's Department

Civil and Environmental Engineering and Engineering Mechanics


Stander Symposium project, School of Engineering

United Nations Sustainable Development Goals

Sustainable Cities and Communities; Industry, Innovation, and Infrastructure

The Safety Impact of Raising Speed Limit on Rural Freeways in Ohio