Visibility is one of the most important factors for driving safely. We know that a windscreen should be repaired or replaced, if it is chipped, cracked or scratched. But what do we know about worn windscreens?
For the reason that your windscreen get continuously damaged by windscreen wipers and bombarded by rocks, sand and dirt, it will wear and degrade over time. As a result, a worn windscreen increases the risk of glare meaning that the driver does not see objects or persons on or near the road in time.
Recently the Swedish National Road and Transport Research Institute (VTI) has done a simulator study, where the behaviour of 24 drivers has been studied using three windscreens, a new one, one driven 150,000 km and another driven 350,000 km. In the test the glare was simulated by using a lamp as sunlight. All drivers drove the same loop three times, whereby it had to pass two obstacles. The test persons experienced the driving test as relatively realistic. The test results prove that sight distance of worn windscreens is reduced by 65% on average, because obstacles were discovered later with a used windscreen. The driver used harder brake power and took a more powerful action to avoid the obstacle, which decreases traffic safety.
|Collision with obstacles|
|New windscreen||0% hit obstacle|
|Windscreen driven 150,000 km||4% hit obstacle|
|Windscreen driven 350,000 km||8% hit obstacle|
The results indicate that there is a large accident risk when driving with a worn windscreen in difficult conditions such as oncoming lights. Knowing that a considerable amount of vehicles in traffic has a windscreen with a mileage over 150,000 km, we should take this problem seriously.