You have to feel sympathy for Thor, the driver who ignored the lane departure warning in his pristine new Volvo XC90. The SUV drifted into a ditch at 50mph, after which it was launched into the air before crashing with a thud into an embankment.
It’s just as well that Thor and the family he was carrying aboard his bright orange XC90 are crash test dummies, because even at that speed there was a surprising amount of violent energy dissipated during the accident.
The hapless piece of driving by Thor – I’m not sure if Volvo gives names to all of its crash test dummies – occurred at the car firm's test facility in Gothenburg.
The Swedish manufacturer proudly claims that the new XC90 is the “safest SUV in the world” and is keen to highlight how it has refined its crash test procedures to take into account the kind of real-life incidents that occur on roads around the world.
Real-world accidents are more nuanced than the typical crash tests we’re used to seeing, where a car slams head-first into an unyielding concrete wall. After studying its own vast accident database for common types of real-life incidents, Volvo developed three tests called ‘Ditch’, ‘Airborne’ and ‘Rough Terrain’ for evaluating the consequences of scenarios where a car might run off the side of the road.
The ‘Ditch’ test that Thor got so wrong is designed to replicate the bouncing movement when driving into an 800mm-deep ditch at 50mph and then impacting an embankment.
“We built a replica of a real-life scenario, which you do find on many rural roads,” says Thomas Broberg, a senior technical advisor for safety at Volvo. “As the car gets airborne, it is quite a rough event. The accident involves high speed, vertical loads and a hard landing, and the car’s occupants move around in many different directions. Injuries to the lower spinal area can occur in these types of collisions.”
Volvo has good cause to focus on this type of accident, says Broberg. “From our data, we see that from 1991 onwards that we have made significant improvements when it comes to reducing the total amount of injuries in total in our vehicles," he says.
“But if we look specifically at the type of injuries occurring in these types of run-off road situations, we have not made the same amount of progress in reducing them. So of course, working with our zero-fatality ambition, this is an area we have to address.”
Improving protection means pre-empting what might happen to the car and its occupants during the accident.
Having determined the chronology of such an accident and the forces at play, Volvo can set about trying to counteract its effects on the occupants. The first step is to develop sensor technology so that the car knows when it is leaving the road. This involves building up a data bank of scenarios that could occur on different roads around the globe.
“This is the type of complex scenario we have to tackle, but they are quite unpredictable, because if you look along the side of any road, there are so many possible scenarios that could unfold,” says Broberg.
The next step is to ascertain what protection the occupants require. Broberg says: “Occupant posture is an important factor in the injuries sustained, so by using electric seatbelt retractors, we can help position the occupant in these situations and keep them in a better posture during the sequence of events.