Snow has begun to fall across the UK and motorists are being warned of the travel chaos likely to result.

A 100-mile wide blanket of snow is moving cross-country with drivers already struggling with the conditions. Police in Sussex reported “mayhem” as drivers made their way on frozen roads — some covered in snow following the weekend’s blizzard. The Met Office has warned motorists across the country to be wary of the early morning icy conditions.

Commuters in London, Birmingham, Liverpool, Leeds and Sheffield may see the worst results. As well as coastal areas of East Anglia and Lincolnshire that could be particularly treacherous, forecasters warned.

Experts warned that road gritting may not even work as this weekend’s freeze could render salt ‘virtually ineffective’.

The AA has issued advice to help motorists deal with cold, snow and ice during the winter months. The organisation says the number of breakdowns nearly doubles during very cold spells, and say extra patrols are on call.

Experts have given advice for driving, relating to electrics, antifreeze, tyres and visibility. A statement on the AA’s website includes the following advice:

Batteries and Electrics:

–       Lights, heaters and wipers put high demands on the car battery. If your driving is mainly dark rush-hour trips, the battery will give out eventually. Batteries rarely last longer than five years. Replacing one near the end of its life can save a lot of time and inconvenience at the side of the road.”

–       Avoid running electrical systems any longer than necessary – turn the heater fan down and switch the heated rear window off once windows are clear.”

 Antifreeze:

–       A continuous squealing noise as soon as the engine is started is a sign the water pump is frozen – it’s the fan belt slipping on the pulley. The cylinder block could be frozen too.

–       Stop the engine immediately and allow it to thaw out. This may take several days unless the car can be moved to a heated garage.

–       If the car begins to overheat a few miles from home it’s likely that the radiator has frozen preventing coolant from circulating. Stop straight away to avoid serious damage and allow the radiator to thaw.

–       Antifreeze costs only a few pounds, but a frozen and cracked engine block will cost hundreds of pounds to repair.”

Visibility:

–       Keep the windscreen and windows clear, and to make sure wipers are switched off in the park position when leaving the car, when there’s risk of freezing.

–       Make sure that all bulbs are working and that lenses are clean. If you have to clear snow from the car it’s important to clear it from the lights – front and back – as well as from the glass and roof.

Tyres:

–       The AA recommends at least 3mm of tread for winter motoring, and certainly no less than 2mm. Do not reduce tyre pressures to get more grip – it doesn’t work, and reduces stability.

–       It’s rare to need snow chains unless you live in an isolated area hit with heavy snow, and where the roads are not cleared. They must be removed to drive on a metalled road without a reasonable covering of snow.

–       Consider changing to winter tyres or all-season tyres – these have a higher silica content in the tread which prevents it hardening at lower temperatures, and therefore gives better grip in cold, wet conditions.

Motorists should get up 10 minutes early to allow time to “prepare the car”. Motorists should clear all windows using a scraper and de-icer, and use a cigarette lighter to warm a key for a frozen lock. The AA advised not to breathe on the lock, as the moisture will condense and freeze.