New large-scale analysis of more than 300,000 road collisions between 2017 and 2021 has detailed the extent to which heavier, larger vehicles are putting cyclists and pedestrians at an increased risk of suffering serious or fatal injuries in the case of a collision.

The research comes thanks to the Vias institute, formerly known as the Belgian Road Safety Institute, and saw the characteristics of vehicles involved in collisions analysed. Factors such as mass, height and age were noted alongside the severity of injuries sustained by the vehicle’s occupants, and those suffered by occupants of any other vehicle involved, or pedestrians and cyclists.

The height of a car’s bonnet was seen as one factor that can increase the risk of fatal injuries to vulnerable road users. A pedestrian or cyclist hit by a car whose bonnet is 90cm high was found to have a 30 per cent greater risk of fatal injuries than if they are hit by a vehicle whose bonnet is 10cm lower.

When the researchers looked at vehicle type there were also implications for cyclists, the risk of serious injury increasing by 90 per cent and the risk of fatal injuries increasing by almost 200 per cent when a pedestrian or cyclist is hit by a pick-up vehicle.

“Two-speed road safety”

Vias concluded that the increase in heavy, tall and powerful cars on the roads meant “two-speed road safety”, whereby the risks to the larger vehicle’s occupants and other road users is drastically different.

SUV on a road
SUV on a road (Justin S. Campbell, CC BY-ND 2.0 on Flickr) (Image Credit: Adwitiya Pal)

“On the one hand, passengers in these more robust vehicles are increasingly safer; on the other, vulnerable users and occupants of smaller cars (lower mass and power) are increasingly at risk of serious or fatal injuries,” the study concludes, saying it is “essential” to slow down the increasing production of heavier cars.

“Of course, the increase in the mass of cars is partly explained by the massive presence of driving aids, but also by increased comfort, greater sound insulation and increasingly thick body pillars. This study clearly shows that it is essential to slow down this increase, to move towards a more homogeneous fleet and to better protect vulnerable users in the event of collision with cars,” Vias says.

Disparity in weight leading to disparity in risk was also seen when looking at collisions involving two cars. In the case of a crash between a 1,600kg car and a 1,300kg car, the risk of fatal injuries decreases by 50 per cent for the occupants of the heaviest car, while it increases by almost 80 per cent for the occupants of the lighter car.

The research around taller bonnets posing more danger to cyclists backs up another study published in April of this year. Research from the Insurance Institute for Highway Safety, in the United States, found that SUVs’ large front ends are more dangerous to cyclists than other cars.

SUV (from Unsplash)
Modern SUV with a large front-end (Image Credit: Adwitiya Pal)

The study found that crashes with SUVs resulted in 55 per cent more trauma and 63 per cent more head injuries than crashes with other cars, owing to taller front-end designs, the lead author suggesting that vehicles with taller front ends run down vulnerable road users, while other cars tend to vault collision victims over.