No Chance of Survival

No Chance of Survival

The Devastating Consequences of Colliding with a Tree

Dec 2016

At DEKRA’s crash test center in Neumünster, a Peugeot 406 estate was accelerated to 98 km/h with help from a cable and then thrown sideways against a post. Anyone who has seen these pictures hopes to never experience a similar situation on the roads. The vehicle is completely torn apart, parts fly through the air and in the interior, nothing is the same as it has been. The Peugeot is destroyed beyond all recognition because the artificial tree has gouged into the entire length of the chassis on collision. The side airbags did deploy, but according to DEKRA they would have offered hardly any protection. In short, none of the occupants would have survived this scenario.

“With this test, we wanted to highlight the immense forces created in a collision with a tree and that, depending on the speed, there is really no chance of survival for the occupants of a car,” said Jens König, head of accident analytics and accident research at DEKRA Automobil GmbH. “The risk of being killed in a collision with a tree is twice as high for the occupants compared with other obstacles,” pointed out Jens König. In a collision with a tree, all the impact energy is concentrated on a small area of the vehicle. When the side or the roof of a vehicle collides with a tree, the passenger cells are so severely deformed that there is no chance of survival for the occupants.

With the crash test, accompanied by introductory presentations from DEKRA accident researchers Markus Egelhaaf, Alexander Berg and Luigi Ancona, DEKRA confirmed what is also shown by annual car accident statistics with distressing consistency: collisions with trees on the side of the road can be identified by the high accident severity. According to information from the Federal Statistical Office (Destatis), in 2015, 603 people in Germany were killed in road accidents after collisions with a tree. This counts for around 17.4% of all 3,459 road users killed. Rural roads carry the greatest risk here. In 2015, 517 people were killed in collisions with trees in Germany, equivalent to around 26% of all traffic fatalities on rural roads. In comparison, in 2015, 2,175 people were killed in road accidents on rural roads in France, 316 of which were collisions with trees. This is equivalent to around just 15%. In Italy, the problem appears to be slightly less severe. In 2015, 1,495 people were killed in rural road accidents, 127 of which were collisions with trees, which is just under 9%.

Today, infrastructure measures hold huge potential for minimizing the number and consequences of accidents involving collisions with trees on the side of the road. For example, crash barriers offer protection if positioned a suitable distance away from the tree, whenever possible. In this case, the crash barriers can be warped and therefore absorb energy. Two-wheeled drivers can also be effectively protected by suitable designs. Furthermore, bushes and shrubbery also offer reasonable safety-related variations on road design by ensuring that vehicles are stopped by something large and relatively soft. Speed limits and overtaking bans can also ultimately contribute to improving safety on sections where accidents are more likely. Checks support compliance with these provisions.