Winter Tires Shorten Braking Distance

26 Oct 2022
“Winter tires are essential for anyone who uses their car regularly in the winter,” says DEKRA tire expert Christian Koch. “Winter tires increase driving stability, shorten braking distance, and reduce the risk of skidding on slippery winter surfaces.” But this all requires the tires to have sufficient grip, so they must not be too old and still need to have a sufficient tread.
In Germany, winter tires are a legal requirement in certain situations. The law states that in wintry road conditions – specifically black ice, hard-packed snow, slush and slippery frost – vehicles cannot be taken out on the road unless they are fitted with suitable winter tires. Winter tires are deemed suitable if they were produced in 2018 or later and bear the alpine symbol (a snowflake inside a mountain). This symbol replaced the “M+S” marking.
In Austria, cars must have winter tires on all four wheels or snow chains on at least two drive wheels between November 1 and April 15 in the event of wintry driving conditions like snow, slush or ice. Switzerland does not mandate winter tires for cars, but they are recommended in the event of wintry weather, as hindering other drivers can result in a fine. Drivers can also be deemed jointly liable if they are involved in an accident while their vehicle is fitted with summer tires. France also does not make winter tires obligatory across the board, although they can be mandated in on traffic signs, especially in mountainous regions. In Italy, too, winter tires can be temporarily required on certain routes. Drivers must use winter tires or carry snow chains between October 15 and April 15 in the northwestern Aosta Valley region, and between November 15 and April 15 in Alto Adige in the north-east.
Recent years have seen all-season tires become increasingly popular among drivers. “These tires need to bridge the gap between summer and winter tires, making them at best a compromise,” says Koch. “They can sometimes represent an alternative for people who drive infrequently and mostly travel within urban areas.” This may be the case for those who can turn to public transportation in the event of ice and snow. “In this case, drivers need to critically assess their own decisions on the road and the routes they choose to travel,” says Koch.
Regardless of what type of tires are fitted (summer, winter, or all-season), they can only do their job adequately if they have a sufficient tread depth. The legally mandated tread depth in Germany is 1.6 millimeters (2/32”). DEKRA recommends a minimum tread depth of 4 millimeters (5/32”) on winter tires, as is the legal requirement in Austria. Anything less can significantly jeopardize the tires’ ability to grip in snow and prevent hydroplaning.