Bad weather predicted for the South-east, combined with the start of half-term holidays and the usual Friday jams are set to cause chaos on the motorways. Traffic levels are expected to be 10-15 per cent above the normal Friday levels, which are already the worst in the week.
Traffic experts say that contrary to conventional wisdom, it is not summer bank holidays or Easter which are the worst time on the roads but the autumn half-term because a greater proportion of people use cars than in the summer.
A spokesman for Trafficmaster, the company which provides in-car electronic information on the state of congestion on the motorways, said that the company predicts 314,000 vehicles will be on the motorways during the afternoon peak, bringing speeds down to 30mph.
The company has sensor units mounted at two-mile intervals on much of the motorway network and according to the company's records, the seasonal variation in traffic congestion on motorways is pronounced, with the peak period between October and mid- December. The second busiest period is January to May. But once the summer holiday season starts congestion reduces as longer daylight hours mean that more people drive later, reducing the effect of the peak.
Trafficmaster says that a myth surrounding traffic congestion is that bank holidays are a nightmare on the motorways. The spokesman said: "Apart from hot spots in the West Country and on the South Coast, bank holidays result in a reduction in congestion, especially in the London area." In fact, the company says that on the last three Easter Mondays, the congestion in the morning and evening on the M25 has been "negligible".
The RAC calculates that as many as 105,000 person hours could be wasted in traffic jams today. The RAC advises people to travel outside tomorrow's peak period, pointing out that next week congestion levels during the day will be down by around a third because of all those people away for half-term week.