NCHRP Report 537


Book Description













Roadside Design Guide


Book Description

This document presents a synthesis of current information and operating practices related to roadside safety and is developed in metric units. The roadside is defined as that area beyond the traveled way (driving lanes) and the shoulder (if any) of the roadway itself. The focus of this guide is on safety treatments that minimize the likelihood of serious injuries when a driver runs off the road. This guide replaces the 1989 AASHTO "Roadside Design Guide."










Guidelines for Attachments to Bridge Rails and Median Barriers


Book Description

The objective of the research project was to collect crash test data relating to bridge rails and median barriers, to collect information about common attachments to traffic barriers, and to evaluate this information for the purpose of developing guidelines for the design and placement of traffic barrier attachments. A comprehensive review of full-scale crash testing of bridge rails and median barriers was conducted in order to establish Zones of Intrusion (ZOIs) for traffic barriers. The primary goal of this review was to identify the extent that a pickup or single-unit truck intrudes over the top of a traffic barrier during a vehicular impact.




Development of an NCHRP Report 350 TL-3 New Jersey Shape 50-inch Portable Concrete Barrier


Book Description

For roadside work-zones in areas that have opposing traffic flow, safety is enhanced if the temporary barriers incorporate a "glare-shield" that blocks headlight glare from opposing traffic. Currently-available 32-inch portable concrete barriers require the use of an add-on glare shield attached to the top of the barrier. The add-on glare shields are an extra expense and complicate barrier set-up and handling. An alternative solution was to develop a 50-inch high portable concrete barrier which is tall enough to serve as its own glare-shield. Finite element analysis was used to investigate various barrier shapes and connection schemes to identify a successful crashworthy design that would meet requirments of NCHRP Report 350 Test level 3. A 50-inch portable concrete barrier design was developed based on the results of the finite element analyses and was crash tested at the Transportation Research Center in East Liberty, Ohio. The system successfully met all safety criteria of NCHRP Report 350 and has been approved by the Federal Highway Administration for use on the National Highway System as a test level 3 device.




Guidance for the Selection, Use, and Maintenance of Cable Barrier Systems


Book Description

This report provides guidance for the selection, use, and maintenance of cable barrier systems. While cable barrier systems have been in use for more than 70 years, their use has been on the rise and is expected to continue in the future. The increase in use of cable barrier systems has been attributed to the success rate in keeping vehicles from crossing the median, reducing roadway departures, and decreasing impact severity. Due to advancements in cable barrier system technology, installation and repair costs are lower and cable barrier use has increased in varying roadway environments. Safety studies, although limited, have shown that cable barriers help reduce those median cross-over collisions that lead to some of the most severe head-on type crashes. This document will be of particular interest to design, maintenance, traffic, and safety engineering professionals.