External airbags to protect cyclists could feature on future cars
Car manufacturers are constantly aiming to offer potential customers greater occupant safety but it has only been over the last few years that the safety of pedestrians and cyclists has been considered. Euro NCAP only made pedestrian safety and integral part of its annual tests in 2009.
But in the Netherlands, where bicycles are ubiquitous, approximately 200 cyclists (and 70 pedestrians) are killed each year after being struck by a car.
If a car is going faster than 25 mph – the average speed of an accident in the Netherlands – a collision with a bicyclist is usually fatal, and helmets don't help much during an impact of 12 mph or greater.
After receiving a grant from the Dutch government, TNO looked at every detail of a cycle crash, specifically at the impact points at a vehicle's front end, concluding that automatic braking and external airbags positions at the bottom of the windshield would reduce the severity of crashes dramatically.
Using information from a camera mounted on the rear-view mirror, the system preps for a collision, and if the car strikes a cyclist, the airbag will inflate and cushion the rider's impact on the windshield.
The camera diagnostics that initiate the automatic braking and airbag deployment are the result of a year's testing while driving through major Dutch cities in a camera-equipped car.
After all those near-misses with pedestrians and cyclists, the system has been optimized to kick in only when it calculates a high risk of collision.
A similar piece of technology already exists in the new Volvo V40. Its pedestrian airbags are designed to protect those traveling on foot from injury at collision speeds between 12mph and 31mph.
It uses seven sensors around the front of the car to detect the type of impact, and then sends this information to the car's on-board computer for analysis.
If the system interprets the object as a human leg, it first releases the bonnet hinges by firing two pyrotechnic charges. Almost immediately, the airbag inflates, raising the bonnet by 10cm in the process to help absorb some of the impact.