Highways can reveal industry concerns over the ability of standard crash barriers to protect drivers in much heavier modern electric vehicles (EVs), prompting National Highways to commission research in this area.
Barriers are tested to prescribed containment levels - broadly normal, high and very high containment - dependent upon the level of risk and type of hazard that requires impact protection.
But there is no current requirement to test barriers with electric vehicles, National Highways said, despite the fact the electric battery in EVs makes them heavier than similar-sized petrol or diesel cars.
The performance of barriers, also termed vehicle restraint systems, is dependent upon several factors including vehicle weight, speed, angle of impact and site-specific incident considerations.
As weight is a key factor, the worry is that the much heavier electric vehicles could present a greater risk compared to similar-sized petrol or diesel cars.
National Highways has confirmed it is spending £30,000 with TRL on initial research in this area, with the results expected next year. A decision on further research will be taken once National Highways has viewed the early results.
A National Highways spokesman told Highways that 'to our knowledge, there have been no crash barrier tests with electric vehicles undertaken nationally or internationally'.
EN1317 is the main European standard that defines common testing and certification procedures for road restraint systems.
It defines levels of safety barrier performance and tests barriers to different containment levels using factors including vehicle weight, speed and angle of impact.
The standard has not been updated since 2012, and the testing regime required for the common containment levels (N and L levels) uses test conditions that are not in line with the weights of modern electric vehicles.
For instance, the N1 and N2 containment level and L1, L2, L3 and L4 containment levels under EN 1317 test at a weight of 1,500kg. There is an H level which does require a much heavier test. However, Highways understands these containment levels are very rarely used on the highway and are often used in connection with rail lines.
A Model 3 Tesla has a technically permissable maximum laden mass that starts at 2017kg and goes up to 2184kg. Even using the weight of the model 3 with correct fluid levels but no occupants and no cargo, the starting point is 1617kg and goes up to 1779kg.
Leading test facility Horiba Mira told Highways: 'We have not conducted any tests using EVs to the EN1317 test standard as they are currently not listed in the vehicles to be used in the testing to the standard.'
A National Highways spokesman said: 'National Highways are aware of how the size and weight of some cars on the network have increased, particularly with electric and SUV type vehicles.
'Whilst we are currently required to follow the European standard (EN1317) for testing barriers we recognise these requirements have not recently been updated to specifically test these new types of vehicles. We have therefore commissioned research to help us understand future vehicle trends and inform our future standards, and we are working with national and international experts to identify how any changes in the vehicle fleet can be incorporated into the next revision of the British / European standard.
'In the interim, all new high-speed roadside barriers are tested to confirm their performance, against prescribed physical crash testing, as required by the European standard.'
The percentage of electric vehicles is currently estimated at around 5% of all vehicles; however, the number is growing rapidly under social and legislative pressure.
All new conventional petrol and diesel cars and vans are set to be banned from sale in the UK in 2030.
