3 research outputs found
Design Guide for Addressing Nonrecurrent Congestion
No full textNonrecurring traffic congestion, which comprises the majority of total congestion, results from random incidents that cause unexpected delays, such as crashes, weather, and work zones. Road users are frustrated by unexpected delays that can make for unreliable arrival times at their destinations. The delivery of travel time reliability is becoming an emerging business activity and performance measure for transportation agencies to meet the increasing expectations of the public and freight industry. The purpose of this guide is to give transportation engineers, designers, planners, and decision makers an understanding and technical reference on how different high-way geometric design elements can be deployed, in new designs or site retrofit actions, to contribute specifically to the reduction of nonrecurring congestion and travel time reliability improvement on both urban and rural freeways. The guide introduces the nonrecurring and travel time reliability topics and metrics, a catalogue of design elements, and a process for selecting candidate design elements to evaluate for a specific site. For individual design elements, example content includes a description of that element, advantages and disadvantages, factors to consider when selecting the element, applicability to nonrecurring congestion, design criteria and practices, safety effectiveness, typical applications, and costs. In addition, there is an evaluation procedure that allows practitioners to compare alternative design treatments and select the best treatment solution for a specific site
