Traffic is building on the M25 in Surrey due to the unprecedented closure of a section of Britain’s busiest motorway.
A five-mile stretch of the motorway between junctions 10 and 11 in Surrey was closed in both directions at 9pm on Friday while a bridge is demolished and a new gantry installed. It will reopen at 6am on Monday.
National Highways South East (NHSE), in a post on X, formerly Twitter, said there were two miles of tailbacks on approach to the closure at junction 10 on Saturday morning.
Meanwhile, traffic began to build along the main diversion route through Byfleet, West Byfleet, Woking and Ottershaw.
NHSE estimated the average journey time along the diversion route was 25 minutes, assuring drivers of minimal congestion.
Motoring experts say official estimates of congestion levels may be optimistic, while local councillors in areas where motorway traffic will be diverted are anticipating gridlock.
The M25, which encircles London, normally carries between 4,000 and 6,000 vehicles in each direction every hour from 10am until 9pm at weekends between junctions 9 and 11, including airline passengers travelling to and from the UK’s two busiest airports, Heathrow and Gatwick.
National Highways said modelling carried out while it was developing its plans for this weekend indicated vehicles would face delays of up to five hours without mitigation measures, such as urging drivers to stay away.
The government-owned body believes its awareness campaign will help reduce traffic levels by approximately 50%, meaning the length of time added to journeys will be limited to about an hour. An 11.5-mile diversion route has been created to direct motorway traffic along A roads.
National Highways is urging drivers not to use their satnavs to attempt to find quicker alternative routes on minor roads due to fears this could cause significant congestion.
Steve Gooding, the director of the motoring research charity the RAC Foundation, told PA Media: “We must hope National Highways has overstated its dire predictions of satnavs adding to the traffic chaos by taking drivers off the official diversion route, because the temptation to try to skip the queues will be intense, and the impact on actual journey times uncertain.
“Whilst the modelling suggests around an hour might be added to people’s travel time, that will feel optimistic to anyone used to the frustrations of driving round the M25 on days even without major construction works under way.”
St Peter’s hospital in Chertsey has urged people to “only visit if it is necessary” this weekend. It said: “Please be aware of the diversions that will be in place and that there is likely to be considerable congestion in the local area. Please plan your journey allowing extra time as it is likely to take longer than usual.”
The unprecedented closures have led to some school sport fixtures scheduled for this weekend in Surrey to be postponed. Councillors whose wards are on the diversion route expressed concerns about the anticipated disruption.
Malcolm Cressey of Runnymede borough council said: “I think it’s going to be a difficult period but we have to sort out those bridges. I think it’s going to be very disruptive. I would certainly urge anybody to try to avoid the area. It could end up with all sorts of gridlock in our area.”
Tahir Aziz of Woking borough council said: “We’ve never experienced something like this before. It will have a significant impact in this area. It will cause huge disruption and delays, and a lot of traffic jams.”
Four more daytime closures of the motorway will take place up to September. The project, due to be completed in summer 2025, will increase the number of lanes at junction 10, which is one of the UK’s busiest and most dangerous motorway junctions.
Gooding added: “National Highways needs to learn from this weekend’s experience and work closely with neighbouring road managers to minimise the traffic impacts of the further planned closures.
“It must give as much certainty and notice as possible – months rather than weeks – to drivers and hauliers, many of whom will be making trips that can’t be put off to another day.”
