E-mobility: Watch out for the risks, or you're in for a bust

A loud bang, a head-on collision at 70 kilometers per hour. The driver of the pink Renault ZOE massively underestimated the strong acceleration of his electric vehicle and left the lane.

Electric cars differ from conventional cars in several respects. This also has an impact on accidents. Axa's accident researchers demonstrated three possible scenarios at this year's crash tests at the airfield in Dübendorf ZH. The tests opened the eyes of the numerous onlookers to the specific risks that e-car drivers and other road users should not underestimate.

High-horsepower e-cars drive up claims frequency

According to the insurance company, initial evaluations of the claims figures to date show that the claims frequency of electric cars is comparable overall to that of other cars. However, clear differences can be seen by vehicle class. "While smaller e-cars in the micro class and small car segments cause around ten percent less damage than conventionally powered cars in the same vehicle class, the claims frequency for larger, high-horsepower models in the luxury car/SUV category is around 40 percent higher," says Bettina Zahnd, Head of Accident Research & Prevention at Axa Switzerland. The accident researchers see one reason for this in the acceleration behavior of e-cars.

Danger 1: E-cars accelerate faster than expected

Anyone who has ever sat at the wheel of an electric car and pressed the gas pedal knows that these vehicles accelerate very quickly and always with the same force, regardless of the engine speed. "Maximum acceleration is available immediately, whereas it takes a moment to reach maximum acceleration even with high-horsepower internal combustion engines. This places new demands on drivers," Zahnd said. In a survey conducted by the insurer, half of the e-car drivers surveyed said they had to adjust their driving style when switching to an e-car due to the change in braking and acceleration behavior. Increasingly, specific knowledge of the individual vehicle types is important, emphasizes the accident researcher. With e-cars in particular, drivers first have to get used to the changed braking and acceleration behavior before they can operate the vehicle safely.

A crash test (see photo) shows what the consequences of strong acceleration can be, especially with an inexperienced driver at the wheel: An e-car driver is driving on a country road and wants to accelerate only slightly shortly before a right-hand bend. The e-car accelerates more strongly than he expects, so that the surprised driver leaves his lane in the curve and enters the oncoming lane. The oncoming car can no longer brake or swerve in time. The result is a head-on collision in which the two cars collide at around 70 km/h. Both passenger cars are severely deformed. Both passenger cars are severely deformed. Although the drivers are protected in the best possible way by seat belts and airbags, both drivers are likely to suffer moderate to severe injuries, the accident researchers emphasize.

Battery can ignite in case of accident

Based on its experience, the insurance company concludes that an accident with an e-car is similarly dangerous for the occupant as with a conventionally powered car. They would undergo the same safety tests and are equipped with the same safety elements such as rigid passenger cells and airbags. In addition, in the event of a very violent collision, the high-voltage system in e-cars would be switched off to ensure that the vehicle was no longer live.

Depending on the accident, however, the batteries may be damaged and start a fire, he says. "E-cars don't burn more often than other vehicles, but if a battery ignites, it burns very quickly and can hardly be extinguished," Zahnd says. In such a case, he says, the only thing left to do is to get the occupants out of the car as quickly as possible and move them to a safe distance to protect them from burns and toxic fumes.

Danger 2: Silent startup

Residents plagued by car noise are happy to see as many electric cars as possible, because they are very quiet. Starting the engine in particular is barely audible. However, this also has a downside, as a second crash test in Dübendorf shows: The driver of an e-car reverses out of a parking space while an elderly woman with a walker passes behind the car. The driver overlooks the woman - and since the engine cannot be heard, the woman does not notice the car driving off either. She is hit by the car and falls to the ground - in the worse case scenario, this can end with serious injuries.

Install sound generators

According to EU regulations, all new types of hybrid and electric vehicles must be equipped with an acoustic warning signal (Acoustic Vehicle Alerting Systems, or AVAS) to protect pedestrians from July 2019. However, older models are not required to be retrofitted. "We recommend that owners of silent e-cars voluntarily equip them with a sound generator so that other road users can hear them," stresses the accident researcher.

Attention assistance systems

E-cars have another special feature: they are increasingly equipped with driver assistance systems, as are all newer vehicle models. However, e-car drivers are generally more interested in technical innovations, are familiar with more assistance systems and also use them more frequently, as a comparison of the survey results of e-car drivers and others shows. For example, 99 out of 100 e-car drivers whose vehicle is equipped with autopilot say they also use it, more than half even often or always, most frequently on the highway and on interurban roads.

Axa's Accident Research & Prevention department has demonstrated in various studies that driver assistance systems (DAS), especially the emergency brake assistant and the electronic stability program (ESP), can help prevent accidents. However, as automation increases, so does the risk that drivers will blindly trust the technology ("over-reliance"), according to the insurance company. Various accidents are already known today in which - suspected or proven - the driver had too much trust in a system. A third crash test in Dübendorf illustrates what can happen: an e-car driver is driving on the highway with Autopilot switched on, which takes over longitudinal and lateral guidance. The driver trusts this technology and allows himself to be distracted - even though, according to current legislation, he must always be focused on the traffic. In the area of a highway junction, the assistance system reaches its limits and immediately returns the driving task to the driver. The driver should react immediately, but because he was distracted, he reacts too late. The car collides head-on at around 100 km/h with an impact absorber. Although this absorbs more energy than, for example, a concrete pillar, moderate to severe injuries to the driver must still be expected in this violent impact.

Conclusion

In principle, e-cars are just as safe as other vehicles. However, drivers and other road users must adapt to their special features and find the right way to deal with them. The same applies to driver assistance systems, says Bettina Zahnd. But all available systems would have to be constantly monitored by the driver. They could support the driver, but one should not rely on them too much in order not to endanger one's own safety and that of others, concludes the accident researcher.

Tips for e-car drivers

• Take the time to get to know the e-car.
• Be aware that the engine is not audible, and pay particular attention to pedestrians or other road users who rely on hearing an engine sound.
• Accelerate very gently at the beginning to get to know the acceleration behavior. As soon as the accelerator pedal is released, energy is recuperated. This causes the car to decelerate more than without recuperation. As an e-car driver, you must take this behavior into account when you drive.
• Don't rely too much on technology. All assistance systems available today must be constantly monitored.
• Place the rescue card (www.rettungskarte.ch) on the driver's side under the sun visor.

Source: Axa