After All These Years Blunt-End Guardrails are Still Spearing Cars on U.S. Roads

John C. Glennon, D. Engr., P.E.
January 2012 (copyright)

Ran-off-road crashes are the most prevalent kind of crash on U.S. rural roads. Each year, almost 50% of all traffic fatalities result from vehicles that run off the road and roll down steep embankments or impact fixed objects.

The most desirable method to reduce serious roadside crashes is to provide reasonably wide clear zones with relatively flat slopes that are free of fixed objects. For objects such as signs, light poles, and utility poles that cannot be removed, various breakaway devices have been found to be effective. When reasonable clear zones cannot be achieved, guardrail can be installed to keep errant vehicles on the roadway and shield them from the consequences of more severe roadside hazards. Yet guardrail itself is a fixed object, one that can cause serious injury if not designed or installed for maximum crashworthiness.

The guardrail end condition is one design feature that can adversely affect the severity of an impact. This discussion is intended to draw attention to the travesty associated with blunt-end (a.k.a., spoon or fishtail end) guardrails that have been around for over 60 years on U.S. roadways. When these
guardrails are impacted at their upstream end, the rail very often will first penetrate the grill, wheel well, or side door of an impacting automobile and then pass through the passenger compartment. Any passenger sitting in the path of the piercing rail can be either lacerated, or impaled, or sometimes even decapitated.

Early Solutions

Solutions for these serious blunt-end guardrail impacts can be documented as early as 1964, as excerpted below:

This issue was brought into national focus in 1967 by the now-famous Yellow Book published by the American Association of State Highway Officials (AASHO), as excerpted below:

Although the flared-and-anchored end treatments may have lessened both the number and sometimes the severity of vehicle crashes on those guardrail approach ends where they were used, spectacular impalements continued even on these improved designs.

Although increasingly better guardrail end designs began to emerge after the Yellow Book, blunt-end guardrails still remain on some highways today.

Turn Down Ends

The next major improvement, which became popular during the late 1960's, was the turned-down end where the rail was bent down and twisted 90 degrees to where it was anchored flat on the ground.

Although these turned-down end treatments were successful at preventing vehicular impalements, several years of field experience and crash testing showed their tendency to not only vault and roll vehicles but also to channel vehicles into an impact with large objects that the guardrail was intended to shield. The turned-down end treatment was implemented extensively in several states in the 1960's and 1970's but came into disfavor in the 1980's, and was widely discontinued in the early 1990's.

Breakaway Cable Terminals

In the early 1970's, the breakaway cable terminal, or BCT, was developed as an alternative to minimize both the spearing and rollover tendencies of earlier end treatments.

For end impacts, the first two posts were designed to break away allowing the rail to bend away from an impacting vehicle. A cable, which anchored the rail to the ground, allowed the beam to function in tension when a side impact occurred near the end. The BCT was the most widely used end treatment for about 20 years.

New Energy Absorbing Terminals

Because of moderate to high impact decelerations, the BCT was not only modified to produce the slightly improved ELT and MELT variations, but eventually gave way to a new generation of energy absorbing end treatments.
Perhaps the most effective guardrail end treatments available today are a variety of proprietary energy absorbing devices, such the ET-2000 extruder, the BEST terminal, and the SKT-350 terminal. These devices, not only prevent vehicle impalements but also allow impacting vehicles to decelerate at a rate tolerable for vehicle occupants.

The Continuing Directives

Over the years, various directives progressively discouraged first blunt ends, then flared-and-anchored ends, then turn-down ends, and finally BCT ends. Because of the several widely-recognized effective energy absorbing end treatments, the Federal Highway Administration in 1994 issued a directive aimed or eliminating all blunt ends and turn-down ends and requiring that no new BCT's be installed. This directive was followed up by a policy resolution of the American Association of State Highway and Transportation Officials dealing with the same issues. But because blunt ends and turned down ends continue to exist, in 2011 a subcommittee of the Transportation Research Board added their endorsement to ending both blunt ends and turned-down ends within the clear zone on roadways with operating speeds in excess of 48 kph. They also endorsed the newer end treatments that meet appropriate test criteria. Their endorsement reads as follows:

The Current Situation

Despite all of these technological advances, many older sections of guardrail still exist with non-crashworthy ends, particular on city, county, township, and parish roads. Then too, particularly in the smaller of these jurisdictions, new installations and replacements continue to be outfitted with blunt ends. In addition, many of these smaller jurisdictions have bridge rails that can spear impacting vehicle because they are fabricated from angle iron or dimensional pipe. A few faulty guardrails are shown below.

The Alarming Evidence

Below several recent photos show the mayhem that results when vehicles impact blunt-end guardrails on U.S. roadways.


About the Author
Dr. John C. Glennon is a traffic engineer with over 45 years experience. He has over 120 publications. He is the author of the book "Roadway Safety and Tort Liability" and is frequently called to testify both about roadway defects and as a crash reconstructionist.


NOTICE: This copyrighted internet paper and our others, which can be accessed by clicking on OTHER PAPERS, are considered dynamic entities that may be updated or expanded at any time. If you have a critique, comments, additional information, or would like to see additional material in the paper, please email us at

john c. glennon, Book , books,pavement edge drop expert, pavement edge drop off expert,guardrail expert, work zone safety expert, construction zone safety expert, roadway hydroplning expert, traffic engineering expert, traffic sign expert, traffic signal expert, pavement marking expert, highway safety expert
Crash : John C. Glennon, Chartered Contact Us Links Home