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Speed Reduction Mitigation Strategies on Rural Highways at Two-Way Stop Control Intersections and Curves

The relationship between speed and safety is characterized by the physics of vehicle motion. Reduced speeds can likely yield safer driving and various techniques are adapted to reduce the speed at high-risk locations though some of the techniques may not be effective sometimes to reduce the driver speed to a recommended level.

Rural roads are susceptible to a high rate of crashes, and the crash severities tend to be worse, leading to many fatalities and incapacitating-injury crashes. Studies conducted on crashes at rural intersections of state highways and local roads/streets with two-way stop control have proved that the problem was likely poor judgment by the stopped driver on the minor approach of the speed of an oncoming vehicle and/or safe gap in traffic on the major highway.

Several mitigating strategies have been suggested and studied in various studies to improve safety at the two-way stop control rural intersections and at other rural highway segments. In this study, four strategies including solar speed display units, mobile speed trailers, optical speed bars, and colored pavement were tested and assessed in some locations in Kansas.

The results indicated that the solar speed displays and the mobile speed trailers were highly effective in reducing speeds on approaches to intersections and speed transition zones. The solar speed displays and the mobile speed trailers indicated statistically significant reductions in mean speed of from 1.70 mph to 7.1 mph and from 2.5 mph to 7.1 mph respectively. But optical speed bars did not show statistically significant results. And similar to the optical speed bars, the sections of colored pavement did not yield reliable results.

In a word, based on the results of this study, it can be concluded that both the solar speed display units and mobile speed trailers used on this study were effective in reducing speeds at the desired points. In addition, additional studies and longer term studies should be conducted.

Article by Ranjit Prasad Godavarthy, et al, from USA.

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Image by letyeu, from Flickr-cc.

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