Slush planing: why it is dangerous and how to avoid it
Many drivers tend to consider slush planing and aquaplaning to be synonymous. But slush planing is a bit different and a more dangerous phenomenon. Let's figure out the reasons it arises and how to deal with it.
What is Slush Planing?
The term “slush planing” means the slipping of car tyres on slush.
It can occur already at a speed of 50-60 km/h on the winter road. And it is the major difference from aquaplaning, which does not occur up to the speed of 70-80 km/h, even on worn-out summer tyres.
During slush planing, the tyres lose traction as during aquaplaning. The tread responsible for a contact with the road gets clogged with snow, prohibiting self-cleaning, which leads to slipping of tyres. It can result in skidding, increased braking distance even at low speed and so on.
Most often, it occurs at near-zero temperatures, when the snow or ice melts a little and turns into slush, not necessarily deep, 1 or 2 centimetres would be enough.
Car sliding in winter can also be caused by the special reagents (road salt or others) applied to the roadway at low temperatures. The possibility of slush planing remains until they start working.
The modern Rosava and Premiorri winter tyres are designed with resistance to slush planing in mind. Deep and wide grooves on the tread are responsible for the timely removal of water (regardless of its state) when driving on slush.
Small sipes and heavily worn grooves with reduced depth, respectively, cannot remove the slush from the contact patch quickly and clean the tread from it. In such cases, tyres with a directional tread pattern proved to be especially effective.
Also, the softer the tread compound, the better it will adapt to all the imperfections of the road surface, increasing traction on a snow-covered road.
How to Prevent Slush Planing?
Rosava specialists have prepared a few simple rules to help you minimize the risk of slush planing.
1. Change to winter tyres, even before freezing temperatures.
2. Monitor the pressure in the winter tyres. Over- or under-inflated tyres have reduced traction.
3. Monitor the depth and condition of the tread. The tread depth requirements for winter tyres are stricter than for summer tyres. In many European countries, a minimum tread depth of 4 mm is permissible according to the legislation.
4. Maintain a proper distance and select the speed mode according to the weather and the road conditions.
5. For greater driving confidence, practice at an empty car park, or, even better, at a test track to learn how your car behaves with the slush on the road. It is important to figure out not only the braking distance at different speeds but also the behaviour of your car during acceleration.
6. If you feel you are partially losing control because of the slush, try to reduce the speed very smoothly by shifting to a lower gear, preferably without applying the brake pedal. Avoid as well abrupt turning of the steering wheel if possible. Having reduced the speed to 10-20 km/h, continue driving slowly until a dry or cleared section of the road appears.
It is impossible to completely avoid slush planing if you drive frequently. Untimely cleaning of streets by road services or excessive exposure of roads to liquid reagents creates favourable conditions for this phenomenon. Therefore, take into account all external factors, from the condition of the road surface to the tread depth of your winter tyres, when choosing the speed and style of driving in each particular situation on the winter road.