Can electronic stability control replace studded tyres?

Live and Let Die? Life Cycle Human Health Impacts from the Use of Tire Studs

Studded tires are used in a number of countries during winter in order to prevent accidents. The use of tire studs is controversial and debated because of human health impacts from increased road particle emissions. The aims of this study are to assess whether the use of tire studs in a Scandinavian studded passenger car actually avoids or causes health impacts from a broader life cycle perspective, and to assess the distribution of these impacts over the life cycle. Life cycle assessment is applied and the disability-adjusted life years indicator is used to quantify the following five types of health impacts: (1) impacts saved in the use phase, (2) particle emissions in the use phase, (3) production system emissions, (4) occupational accidents in the production system, and (5) conflict casualties from revenues of cobalt mining. The results show that the health benefits in the use phase in general are outweighed by the negative impacts during the life cycle. The largest contribution to these negative human health impacts are from use phase particle emissions (67⁻77%) and occupational accidents during artisanal cobalt mining (8⁻18%). About 23⁻33% of the negative impacts occur outside Scandinavia, where the benefits occur. The results inform the current debate and highlight the need for research on alternatives to tire studs with a positive net health balance.

Studded and unstudded winter tires in fatal road accidents in Finland

OBJECTIVE

The aim of the study was to compare the safety effects of studded and unstudded winter tires based on fatal road accidents.

METHODS

The data included 958 road accidents involving a passenger car or van that occurred in Finland from November to March between 1997 and 2012.

RESULTS

Comparing the proportions of winter tire type in accidents and in general traffic showed that the overall effect of tire type on the number of accidents was not significant, although studded tires reduced fatal accidents by 10-15%. Compared to unstudded tires, studded tires reduced accidents significantly only on bald ice in 2005-2012. Drivers using unstudded tires were more experienced and their profession was more frequently related to driving. In addition, the vehicle age was lower for vehicles with unstudded tires. On the other hand, the state of repair was less pertinent for unstudded than for studded tires. These confounding factors offset their effects to some degree.

CONCLUSIONS

The risk of fatal road accidents in winter between studded and unstudded tires does not differ significantly. However, the accident risk has recently been substantially higher on bald ice for unstudded than for studded tires. The magnitude of this risk difference is difficult to determine without specific information on exposure by road surface.

Does the influence of risk factors on accident occurrence change over time?

A large number of studies have been made to assess the relationship between risk factors and accident occurrence. A risk factor is any factor that makes an accident more likely to occur. Very many risk factors have been identified, for example, being under the influence of alcohol while driving, driving on slippery roads, entering complex junctions, or driving in hours of darkness. Few studies have been made to determine whether the associations between risk factors and accident occurrence remain stable over time. This paper presents examples of studies that have replicated estimates of risk. All these studies were made within a given country, using the same method, to ensure that estimates of risk are comparable. The risk factors included in the paper are: daylight, horizontal curves, junctions, road surface conditions, precipitation, drinking and driving and driver age. For all these risk factors, their association with accidents has changed over time, mostly becoming weaker. A protective factor, snow depth, is also included. Its protective effect has become smaller over time. Possible reasons for the weakening influence of risk factors are discussed.