Motorists are being warned to expect â€œgridlockâ€ as millions of families hit the road for the start of the summer holidays in England and Wales.
Drivers are expected to make more than 34 million leisure journeys over the next fortnight, with more than nine million this weekend, as families head off on their summer breaks.
This Friday is expected to be particularly bad, with the RAC warning an extra 3.4m holiday trips will clash with regular commuter traffic, leading to congestion and hold-ups.
Transportation analysts INRIX are predicting delays of up to one and half hours on some popular routes, and thatâ€™s before any breakdowns or accidents add to the increased journey times.
Among the worst-affected routes are the southbound M40, where hold-ups of 90 minutes are expected; the M5 with delays in excess of an hour; and the A303, with 52 minute delays.
This weekend’s worst roads
Date Worst roads Friday 20 July M40 south, J3a to J1a:1hr 30min delay at lunchtime
M5 south, J12 to J31: 1hr 17min delay late afternoon
M5 north, J31 to J12: 1hr 9min delay mid-afternoon
A303, M3 to A37: 52min delay late afternoon
Saturday 21 July M25 anticlockwise, J23 to J16: 40min delay early afternoon
M1 north, J6 to J23a:20min delay late afternoon
Sunday 22 July M25 anticlockwise, J23 to J16: 30 minute delay at lunchtime
M40 south, J3a to J1a:20min delay late afternoon
Data sources: RAC and INRIX
Drivers are being advised to avoid travelling on Friday afternoon if at all possible and to set off early in the morning on Saturday and Sunday to avoid the worst of the delays.
RAC traffic spokesman Rod Dennis said: â€œThis weekend tends to be one of the busiest on the roads for leisure journeys, second only to Easter and Christmas. On some popular routes, this may well mean gridlock, especially through the second half of Friday when commuters and holidaymakers will be sharing space on the same stretches of the UKâ€™s roads. As a result, it will almost certainly feel like a â€˜frantic Fridayâ€™ for some.
â€œThe next peak after this weekend will be Saturday 28 July according to our research, by which time the vast majority of schools in England and Wales will have broken up for the summer. And if the weather remains fine, that could lead to many more people deciding to jump in the car to enjoy a short notice â€˜staycationâ€™, adding to the weight of traffic.â€
INRIX data scientist Joshua Kidd added: â€œOur data suggests that the UKâ€™s major transport corridors will be worst affected as the countryâ€™s schools break for the summer. As a result, the shortest routes to popular holiday destinations may not be the quickest.
â€œDrivers should ensure they check live traffic reports before setting off and consider using alternative routes to avoid the worst of the congestion. If possible, they should also try to leave early morning or in the evening, as the midday and early afternoon periods will be the busiest times to travel.â€