Winter Tyres and Driving Safety
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In most European countries it is common practice for drivers to fit winter tyres in late Autumn and revert back to Summer tyres in the late Spring, so why is this not the case in the UK?

Ask any British driver about winter tyres and their answer is likely to relate in some way to snow or ice covered roads. Ask a British driver how often they encounter snow or ice and the answer is likely to range from very infrequently to occasionally depending upon where they are located in the British Isles.

The perception that winter tyres only give benefits on snow or ice is years out of date as modern rubber compound technology and advances in tread pattern design means the modern day winter tyre also provides higher levels of road safety on cold and damp road surfaces too. (Perhaps a more apt name for winter tyres would now be "Cold Weather" tyres.

Much progress has been made over the last twenty five years and tyre technology is now at a very advanced level. New vehicle concepts, combined with tyres ideally adapted to requirements, have made driving noticeably safer today. The benefits are persuasive - substantially increased mileage performance, less weight, reduced rolling resistance and considerably shorter braking distances on both wet and dry roads all speak for themselves.

As vehicle design and technology has advanced, tyre design has had to do the same but it is unreasonable to expect one tyre type to provide high safety levels with temperature ranges such as +30C to -15C, both of which have been experienced in Britain during 2003. This is why specialist tyres have been developed over many years. To enable them to develop their potential to the full, there is one crucial aspect - they have to have balanced characteristics.

7C Threshold

Ambient Temperature is a deciding factor on which tyre type provides the highest safety for road users. It is Continental's view that most drivers will adapt driving styles when snow is on the ground and when temperatures drop below zero degrees. Why? Because such conditions are either very visible or very apparent to the driver. However, cold damp road conditions visibly are no different to damp conditions in the warmer months, hence drivers will not adjust driving styles to suit. Therefore it is potentially these latter road conditions which present the highest risk.

Research shows these potentially hazardous conditions are most likely to be encountered when the ambient temperature drops below 7C, which in the UK means between October and April. Also of interest is the frequency of vehicle damage insurance claims, which increases sharply with the onset of the cold season.

Braking on Wet Roads

On damp or wet roads, tyres grip differently - and the braking distance is substantially longer, which means the question of the right tyres and the temperature is even more important. Over 7C - between Easter and October - traditional summer tyres are truly in their element. Between October and Easter - Cold weather winter tyres show distinct safety advantages.

Braking on Snow and Ice Covered Roads

On snow or ice covered roads only winter tyres reduce the braking distance by those vital metres. The comparison shown here proves the point.

Temperature Dependent Rubber Compounds

When ambient temperatures fall below 7C the molecules in tread rubber progressively harden and freeze. This means the tyre is less able to adapt to the contour of the road surface, which in turn reduces grip levels. With winter tyre rubber compounds there is a higher proportion of natural rubber and coupled with extended use of silica technology they minimise the hardening effect at low temperatures allowing the tyre to key into the road surface, resulting in higher grip levels. Together with highly developed multi-sipe tread patterns, the combination is such that no summer tyre can match. The illustrations in this article show clearly that below 7C, whether the roads are covered in snow, ice or simply damp and wet, winter tyres provide a clear safety advantage.

The Importance of Tyre Inflation Pressure

A small amount of maintenance pays great dividends in terms of safety. Only well-maintained tyres perform fully and provide a comfortable ride. Tyres should be inspected regularly for cracks, cuts and bulges, and every four weeks check the pressure on the cold tyre to ensure optimum contact with the road.

The Importance of Tread Pattern Depth

Double-check the tread depth too, because as this decreases, braking distances increase. It's a clear indicator of when to change your tyres -when summer tyres have only 3mm tread depth and winter tyres 4mm.

Winter - The Effects

The winter season can bring many variations in weather type:

• Drivers are 5 times more likely to skid on snow/icy road conditions than they are on dry roads.
  
  
• The number of accidents caused by wet road conditions increases in winter by 267%
  
  
• There are 6393 more accidents involving cars on the UK's roads in winter than there are in summer.
  
  
• 31% of people have had a particularly bad experience whilst driving due to winter weather conditions.
  
  
• 60% of people feel scared or uneasy when driving in winter conditions.
  
  
• 36% of people have found themselves stuck on a journey due to winter conditions. Yet 65% of people spend less than £200 on preparing their car for winter driving.
  
  
• 75% of people would not consider fitting winter tyres.

Information courtesy of Continental.