Crash barrier evidence ‘seriously flawed’, says Corus
Experts in steel crash barrier design have questioned the validity of the evidence on which the Highways Agency has based its recommendation in favour of concrete motorway barriers.
The agency issued an advice note last month stating that concrete should be the preferred option for new crash barriers on motorways, on the grounds of lower maintenance costs.
Dr Aled Roberts, Business Development Manager for Corus Construction and Engineering Products, said the report underlying the HA advice was “seriously flawed”.
Dr Roberts accepted that concrete had some maintenance advantages. But, he said, TRL Report PR/SE903/04 on whole life costs and benefits of safety barriers did not take into account the full costs of foundations and drainage for concrete barriers. It compared steel barriers cast in concrete foundations with concrete barriers on concrete, ignoring the fact that steel barriers can be driven directly into the ground.
Dr Roberts added that the report did not fully quantify the cost of injuries caused by barrier collisions. TRL investigated impacts with steel and concrete barriers on the M25 over two years. Though there were no deaths from direct impact with a concrete barrier in that time, Dr Roberts argued that the M25 is unrepresentative, because congestion limits average speeds and therefore the likelihood of a high-speed impact.
“We don’t feel our feedback on the report was properly listened to,” said Dr Roberts. “We believe that if tested in UK laboratory conditions with modern vehicles under a strict regime such as Corus subjects its barriers to, serious flaws in the safety of using concrete walls would become apparent.”
A claim by the concrete industry that concrete barriers are better at preventing crossover accidents compares normal containment steel barriers with high containment concrete versions, Dr Roberts said. High containment steel barriers would have equivalent performance to their concrete counterparts.