Snow tires are tire

Tire

A tire or tyre is a ring-shaped covering that fits around a wheel rim to protect it and enable better vehicle performance by providing a flexible cushion that absorbs shock while keeping the wheel in close contact with the ground...

s designed for use in winter

Winter

Winter is the coldest season of the year in temperate climates, between autumn and spring. At the winter solstice, the days are shortest and the nights are longest, with days lengthening as the season progresses after the solstice.-Meteorology:...

 conditions, such as snow

Snow

Snow is a form of precipitation within the Earth's atmosphere in the form of crystalline water ice, consisting of a multitude of snowflakes that fall from clouds. Since snow is composed of small ice particles, it is a granular material. It has an open and therefore soft structure, unless packed by...

 and ice

Ice

Ice is water frozen into the solid state. Usually ice is the phase known as ice Ih, which is the most abundant of the varying solid phases on the Earth's surface. It can appear transparent or opaque bluish-white color, depending on the presence of impurities or air inclusions...

. They are an alternative to the use of snow chains

Snow chains

Snow chains, or tire chains, are devices fitted to the tires of vehicles to provide maximum traction when driving through snow and ice....

.

Snow tires are usually tires with a different rubber composition from all-weather tires. Cold-weather tires include a greater percentage of natural rubber and silica so there is not as much hardening as found in synthetic rubber in cold conditions: they provide better traction at lower temperatures. Snow tires provide more small-tread areas, increasing traction

Traction

- Engineering :*Forces:** Traction , adhesive friction or force in the context of vehicle** Traction vector, in mechanics, the force per unit area on a surface, including normal and shear components...

 on snow and, in wet conditions, allowing water to escape from under the tire more easily. This reduces the risk of hydroplaning. In much of Scandinavia, snow tires have metal studs to improve grip on packed snow or ice, but such tires are prohibited in most other countries for the damage they cause to the road surface. Snow tires do not eliminate skidding on ice and snow, but they greatly reduce the risk.

Regional symbols and rules

North America

In the United States and Canada, a "snowflake on a mountain" symbol means that the tire has exceeded the industry requirement for a reference (non-snow) tire.

Europe

In Europe, requirements for snow tires vary by country: in Austria, Estonia, Finland, Germany, Norway, Romania, Slovenia and Sweden, the use of snow tires is a legal requirement during winter months (usually November to mid-April) or if snow or slush is present on road surfaces: failure to comply can result in on-the-spot fines from the police. Andorra

Andorra

Andorra , officially the Principality of Andorra , also called the Principality of the Valleys of Andorra, , is a small landlocked country in southwestern Europe, located in the eastern Pyrenees mountains and bordered by Spain and France. It is the sixth smallest nation in Europe having an area of...

, Italy and Switzerland all recommend snow tires but do not require them. Snow chains

Snow chains

Snow chains, or tire chains, are devices fitted to the tires of vehicles to provide maximum traction when driving through snow and ice....

 fitted to tires are required in Andorra, Austria, France, Germany, Italy, Norway and Switzerland in certain winter conditions.

Although there is no legal requirement to use winter tires, drivers in the United Kingdom are encouraged to use them by motoring organisations such as the AA

The Automobile Association

The Automobile Association , a British motoring association founded in 1905 was demutualised in 1999 to become a private limited company which currently provides car insurance, driving lessons, breakdown cover, loans and motoring advice, and other services...

, following the adverse winter weather conditions of 2010

Winter of 2010–2011 in Europe

The winter of 2010-2011 in Europe began with an unusually cold November caused by a cold weather cycle that started in southern Scandinavia and subsequently moved south and west over both Belgium and the Netherlands on 25 November and into the west of Scotland and north east England on 26 November...

. Conversely, the same drivers were discouraged from using winter tires by car insurance companies

Vehicle insurance

Vehicle insurance is insurance purchased for cars, trucks, motorcycles, and other road vehicles. Its primary use is to provide financial protection against physical damage and/or bodily injury resulting from traffic collisions and against liability that could also arise therefrom...

 who, owing to a failure to understand the safety benefits, reportedly charged higher premiums to drivers who fit winter tires. This has since been clarified as incorrect practice by the Association of British Insurers

Association of British Insurers

The Association of British Insurers or ABI is a trade association made up of insurance companies in the United Kingdom.-History:The ABI began in 1985 after several specialised insurance industry trade associations, including the British Insurance Association, the Life Offices’ Association, the Fire...

(ABI).

Since July 2008, the Czech Republic uses the Europe-wide road sign requiring the use of snow tires in marked mountainous areas during winter. The duration of obligatory snow tire use was originally November – April (Ordinance 208/2008 Sb.). This was later changed to November – March (Ord. 91/2009 Sb.).