Crashes Caused by Unsafe Pavement Edges
Unsafe drop-offs– the area between the edge of the road’s pavement and the shoulder, can be dangerous and sometimes deadly. The height difference between the pavement and shoulder can cause the driver to lose control, then try to return to travel lane, which can cause a sudden twist, may cause the car to fishtail or cross into the other lane and collide with oncoming traffic. Estimates are that 11,000 people are injured and about 160 people are killed annually. A angled drop-off 30 degrees is safer than a vertical drop-off. The drop-off has been said to range from 1.5 to 3.0.”
There are no mandatory national standards the require a specific level of pavement edge maintenance. However AASHTO (American Association of State Highway and Transportation Officials) and FHWA (Federal Highway Administration) do provide some guidance as well as the National Cooperative Transportation Research Program studies and reports.