Purpose

The purpose of this memorandum is to bring to your attention two primary issues related to guardrail end terminals that will require you to take action. As you are aware, we have been closely examining the performance of guardrail end terminals. It’s recognized that there are installation and maintenance challenges with these devices. As the construction season starts, and after the heavy winter, this is the appropriate time to pay particular attention to installation and maintenance issues. In this memo, FHWA emphasizes the need to have in place policies and procedures to evaluate the selection of roadside safety hardware relative to the roadway type, configuration and terrain; ensure its proper installation and maintenance; and periodically evaluate its in-service condition. In addition, we are aware there are some obsolete, non-crashworthy guardrail end terminals that still exist on the nation’s highway system. We have raised awareness regarding these terminals through previous memoranda issued over a number of years. We strongly recommend that you encourage the removal of pre-NCHRP-350 guardrail end terminals.

Background

It is FHWA policy that roadside safety hardware installed on the National Highway System (NHS) should be in compliance with the crash testing and evaluation criteria contained in the Manual for Assessing Safety Hardware (MASH) or its predecessor the National Cooperative Highway Research Program (NCHRP) Report 350. Devices that are compliant with either of these two sets of criteria are currently considered crashworthy devices.

It is critical that devices be installed and maintained properly so they are in the best position to perform as designed and tested. Attached is a technical brief titled "Selection, Installation, and Maintenance of W-beam Guardrail End Terminals" which highlights general guidelines regarding the selection, installation, and maintenance of W-beam guardrail end terminals. In addition, common issues of concern are identified with generally accepted practices to address these concerns.

Even when a successfully crash tested device is properly selected, installed, and maintained, individual crashes in the field are unique events and may result in performance that was not observed during crash testing. For this reason, a crash tested device should be monitored for its in-service performance, as indicated in both NCHRP 350 and MASH.

It is known that roadside safety hardware installed prior to the implementation of NCHRP 350 in 1993 remains on the NHS or other roadways across the nation. However, as indicated in the FHWA action memorandum, "Traffic Barrier Safety Policy and Guidance," dated 9/29/1994, non-crashworthy hardware should be removed and replaced with crashworthy roadside hardware at the earliest possible opportunity in concert with the maintenance of the roadway. It has been more than twenty years since that memo was issued and devices listed in that memo are still in service. We strongly recommend that pre-NCHRP 350 guardrail end terminals be removed and replaced.

Action

Please share this memorandum and its enclosure with your State DOT and any city, county or municipality in your State with responsibility for the operation and maintenance of their roadways.

Please ask them to review and, if necessary, update their policies, procedures, standards, and guidelines relative to the selection, installation, maintenance, and in-service evaluations of crashworthy roadside safety hardware on their roadways, specifically:

1. Relative to installation and maintenance of crashworthy roadside safety hardware, it is strongly recommended that they put in place the necessary protocols to ensure that any entity installing or maintaining roadside safety hardware, including contractors or State or local personnel, are capable (e.g., trained, credentialed or authorized by the roadside hardware manufacturer for the installation and maintenance of their hardware) of doing this work.
2. Review standard plans and specifications to ensure that only crashworthy devices are used on the National Highway System (NHS).

Finally, strongly encourage the highway agencies to increase their efforts to systematically upgrade pre-NCHRP 350 guardrail end terminals, particularly those that are on the NHS.

Resources

FHWA’s Office of Safety and the Safety and Design Team in FHWA’s Resource Center can provide training and technical assistance that focus on the proper selection, installation, and maintenance of guardrail end terminals to State Departments of Transportation (DOTs). Many states have taken advantage of this resource.

FHWA’s Office of Safety will offer assistance to help set up pooled fund arrangements to conduct in-service performance evaluations.

For more information, accessing the above resources, or if you have questions or comments, please contact Will Longstreet at (202)366-0087 or Nick Artimovich at (202)366-1331.

References

• The September 29, 1994, FHWA memorandum, "Traffic Barrier Safety Policy and Guidance", called for replacement of "blunt ends" and discontinued the use of turned down ends and Breakaway Cable Terminals. The memorandum also suggested a policy to upgrade these terminals.
• The August 18, 1998, FHWA memorandum, "National Cooperative Highway Research Program (NCHRP) Report 350 Hardware Compliance Dates," announced the FHWA-AASHTO Implementation Plan for NCHRP Report 350 hardware. This plan required the upgrade of terminals not meeting NCHRP Report 350 as part of 3R projects on the NHS.
• The October 26, 2004, FHWA memorandum, "Guidelines for the Selection of W-Beam Barrier Terminals" identified several characteristics of W-beam terminals that need to be understood in order to select the appropriate system including site grading, type of terminal, and terminal layout.
• The November 17, 2005, FHWA memorandum, "In-service Performance Evaluation and Continuous Monitoring of Roadside Safety Features," identified the need to routinely conduct in-service performance evaluations of crash tested roadside safety hardware.
• The June 26, 2012, FHWA memorandum, "AASHTO Roadside Design Guide 4th Edition," encourages State DOTs to have a written roadside policy that aligns with the AASHTO Roadside Design Guide, 4th edition.

Attachment

• Technical brief titled "Selection, Installation, and Maintenance of W-Beam Guardrail End Terminals.

Page last modified on June 28, 2017