There is no clear evidence for a safety effect of winter tyres. It has been suggested that, from 7 degrees Celsius (and below) winter tyres are safer than summer tyres: winter tyres are alleged to improve grip and shorten braking distance. There are, however, hardly any crash studies comparing the road safety effect of winter tyres to that of summer tyres. The crash studies that do exist, are limited to comparing winter tyres with and without metal studs. Moreover, these studies use crash figures from countries such as Sweden [72] and Finland [73], where winter conditions are unlike those in the Netherlands.
Tyre tests do not offer a clear picture either. They usually compare tyres of different brands but meant for the same weather conditions (see, for example the summer and winter tyre test of the Dutch ANWB). An exception is the 2009 tyre test of TSC (the Swiss sister organisation of ANWB) [74], which compared summer, winter and all-season tyres in different weather conditions. The results (see Table 4) showed that the differences between snowy and dry roads were particularly evident: on snowy roads, the braking distance of winter tyres was clearly shorter than that of summer tyres, whereas on dry roads this was the other way around. On wet roads, the performance depended on temperatures and the differences were smaller. Yet, the results should be interpreted with caution. It is, for example, unclear how the tests were carried out and if the tested tyres had the same quality. Moreover, it is hard to translate the results to the Dutch situation, because there hardly tends to be any snow in the Netherlands. To allow for an estimation of the road safety effect of winter tyres, more research is therefore required.
Winter tyres are not mandatory in the Netherlands. In other countries, like Germany, they are mandatory for some parts of the year, in some weather conditions, and/or on some roads. More information about the rules abroad can be found on the ANWB website [75].
Table 4. Performance of summer, winter and all-season tyres in different weather conditions [in adjusted form adopted from [74]).
