31-07-2024 | Posted by Joaquín Martí
The larger weight of electric vehicles (EVs) poses a potential problem with guardrails on motorways. EVs can weigh up to 50% more than traditional cars, powered by internal combustion engines (ICEs). The increased mass translates to higher kinetic energy and, hence, to higher impact forces in collisions. Standard guardrails were not designed with those demands in mind.
Last fall, engineers at Nebraska’s Midwest Roadside Safety Facility watched as an electric-powered pickup truck hurtled toward a guardrail installed on the facility’s testing ground. The 3.6-ton Rivian R1T tore through the metal guardrail and hardly slowed until hitting a concrete barrier on the other side.
Road safety officials and organizations noted that the EVs themselves appear to offer good protection to their occupants, even if they might increase risks to the occupants of lighter vehicles. Indeed, the Rivian tested in Nebraska showed almost no damage to the cab’s interior after slamming into the concrete barrier. But the purpose of guardrails is to keep vehicles from leaving the road, particularly in critical areas, such as bridges, cliffs, ravines, etc., where the consequences are likely to be particularly serious. And, of course, the same applies when guardrails separate traffic flows moving in opposite directions.
Incidentally, the Nebraska crash tests, sponsored by the U.S. Army Corps of Engineers’ Research and Development Center, also involved a Tesla sedan, which managed to lift the guardrail and passed under it. Overall, the tests suggested that the current barrier system may well prove inadequate for the increased weight of EVs.
This extra weight stems from the large mass of the batteries that EVs require to offer an acceptable range. This may change in the future, as technology improves the energy stored per unit mass, but right now EVs weigh 30%-50% more than comparable ICE-powered vehicles.
The greater weight and acceleration of EVs also poses other challenges to the road infrastructure, like a faster degradation of the road surface, which will consequently require more frequent rehabilitation.
Principia has worked on several projects dealing with the capacity of motorway guardrails to prevent stray vehicles from leaving the road, while also satisfying a number of additional requirements.
Based on our experience, it might be appropriate for those in charge, nationally and internationally, to consider some of the issues associated with the increasing weight of the vehicle fleet as electrification progresses. Upgrading guardrails or developing innovative systems are some of the possible avenues.
Overall, the larger weight of EVs highlights a gap in current road safety infrastructure. While further research and development are needed, proactively addressing this challenge is essential for ensuring the smooth and safe transition to electric mobility.
