Motorcycle Safety

According to a paper written by Clay Gabler of Virginia Tech titled “The Risk of Fatality in Motorcycle Crashes with Roadside Barriers,” in 2005 for the first time in the United States, motorcycle riders suffered more fatalities (224) than the passengers of cars (171) or any other single vehicle type involved in a guardrail collision. In terms of fatalities per registered vehicle, motorcycle riders are dramatically overrepresented in number of fatalities resulting from guardrail impacts. In the United States, motorcycles compose only 2% of the vehicle fleet, but account for 42% of all fatalities resulting from guardrail collisions. It is very likely that these figures would be similar in other countries and these statistics are getting the attention of highway safety researchers around the world.

Traditionally motorcyclist safety has not been taken seriously into consideration when developing longitudinal barrier testing criteria. Europe recently announced plans to include motorcycle testing into the EN 1317-2 longitudinal barrier testing matrix. The Unites States recognizes the need to do something and is currently evaluating options.

A variety of products have been developed to protect motorcyclists who impact longitudinal barriers. Most of these products, many of which come from Europe, are designed to shield the posts of the steel barrier systems. This is logical since motorcycle riders often are thrown from their motorcycles and are sliding along the ground when they hit the barriers.

I have heard some experts say that they believe that a motorcyclist impacting a concrete barrier, or a steel barrier or a cable barrier system will die. It is just a question of “how dead will you be, 100% or 140% or 160%?” However, the real debate comes from the motorcyclists complaining specifically about the cable barrier systems. They refer to these cable barriers as “cheese cutters.” They cite an accident in October of 2007 in New Zealand where a motorcyclist impacted a cable barrier and the motorcyclist was severed from the waist down. The motorcyclists want the cable barrier banned in New Zealand. This opinion has been voiced in other countries around the world.

Some road experts believe the cable barrier actually is safer for motorcyclists when it is impacted. They explain that the cable barrier steel posts are more likely to fracture when impacted. They also claim the cable barrier will be placed further away from the road because of the working width of the cable barrier.

Both sides of this issue need to be explored and this issue needs to be resolved. The question is simple; are cable barrier systems more dangerous for motorcyclists than steel barriers or cable barriers, are they safer, or are they the same? Your comments are welcomed on this site.

The issue of motorcycle safety and longitudinal barriers will be the focus topic at the AFB 20 (2) Roadside Safety International Research Subcommittee meeting at TRB in Washington DC on Monday January 14 from 3:45 PM to 5:30 PM. This meeting will be held in the Balcony D Room of the Marriott Wardman Hotel. All are welcome to join this meeting to listen to a variety of experts define the problem and then suggest a variety of solutions. Your input to the cable barrier-motorcycle safety issue on this IRF Road Safety Matters blog is strongly encouraged to get as many opinions as possible voices on this topic.

Recommendation on Barrier Specification

Every country around the world should require attestation that a longitudinal barrier meets a recognized performance standard before a longitudinal barrier is accepted for use. The two most acknowledged testing criteria for longitudinal barriers are EN 1317-2 (Europe) and NCHRP 350 (United States and Australia.) The TRB AFB20(2) Roadside Safety Subcommittee on International Research is considering a proposal that would recommend that only longitudinal barrier that meets either EN1317-2 or NCHRP 350 be accepted on projects in countries that currently do not have longitudinal barrier performance specifications. This proposal will ensure that properly tested longitudinal barriers are installed and that these barriers will provide the anticipated protection when they are impacted.

Allowing either the US or European criterion to be used will provide economic benefit for the local road authority through increased competition. Since both testing criteria require basically the same light car test (820 kg vehicle – plus dummy weight in NCHRP 350 and 900 kg vehicle including dummy weight in EN 1317-2, 100km/h and 20 degree impact angle) the limiting factors will be the impact severity of the capacity test and the anticipate number of high center of gravity vehicles. A longitudinal barrier that meets EN 1317-2 or NCHRP 350 should be allowed to be used provided the capacity test impact severity of the barrier is higher than the capacity test impact severity of the specified longitudinal barrier. The impact severities of the different levels of barriers in EN 1317-2 and NCHRP 350 are shown in Chart 1 below.

Chart 1 - Comparison of Impact Severity Levels

(click chart to enlarge)

For example, if a road authority decides the most appropriate longitudinal barrier for a road should be the EN 1317-2 “N-2” classification, then any barrier that has an impact severity greater than 81 kilojoules should be allowed as well. This means NCHRP 350 Test Levels 3, 4, 5 or 6 as well as EN 1317-2 Test Levels N-2, L-1, L-2, L-3, L-4a or L-4b also could be used on this project.

If accepted at the upcoming Annual Meeting in January in Washington DC, The TRB AFB20(2) Roadside Safety Subcommittee on International Research would strongly recommend that all road agencies require that longitudinal barriers meet the minimum performance standards as outlined in EN 1317-2 OR in NCHRP 350. A safety factor should be included when determining the severity level to be specified. If a significant number of trucks are anticipated on the road, a higher center of gravity barrier should be specified. Furthermore, the TRB AFB20(2) Roadside Safety Subcommittee on International Research would recommend that impact severity levels be used to specify the minimum capacity for a longitudinal barrier and that any barrier with a higher impact severity level be allowed to be bid on the project regardless if the longitudinal barrier has been tested to EN 1317-2 or NCHRP 350.