The primary objective of this research study was to evaluate the crash history of bypass routes to determine if there were unusual patterns or changes in the crash history on these routes over the first years of operation. The focus of the evaluation was to collect data at bypass routes opened in recent years in Kentucky. Crash patterns were summarized with recommendations made for countermeasures to reduce the probability of crashes, specifically at intersections, with an emphasis on the early stages of operation. The literature was reviewed, crash data were obtained at nine case study bypasses, and discussions were held with representatives from traffic, design, and construction at various district offices across Kentucky.
The analysis found that the crash rates on the bypass routes are generally lower than statewide rates for the same type of highway. The exception was a higher fatal rate in a few instances. The large majority of crashes occurring on these routes have been at intersections. All of the fatal crashes were at intersections. The most common types of crashes have been an angle crash at stop approaches and rear end crashes at intersections with a traffic signal. There were several opposing left turn crashes at some signalized intersections. The angle crashes at the stop controlled intersections typically involved a driver stopping and then pulling into the path of a vehicle on the bypass. A driver disregarded the stop sign in only a small number of these crashes.
The major change in traffic control which has occurred at the intersections after the opening of the bypasses has been the installation of a traffic signal with this resulting in a large reduction in angle crashes. The occurrence of a large number of crashes immediately after the opening of a bypass was not generally found. The two fatal crashes which occurred on the Morganfield bypass in the first few weeks after opening, in which local drivers disregarded a stop sign, were exceptions to the typical crash pattern found at the other locations.
Recommendations were developed in the general areas of: public information, enforcement, traffic control and design. The recommendations were further divided into those which should be done and those which may be used. The recommendations relate to intersections since this is where the large majority of crashes, especially those resulting in serious injuries, occurred.
Digital Object Identifier
Agent, Kenneth R. and Pigman, Jerry G., "Safety Evaluation of New Roads" (2002). Kentucky Transportation Center Research Report. 248.