Fears closure of M25 will be a 'nightmare' for Essex motorists
It's expected to cause significant disruption for thousands of people
The first planned daytime closure of the M25 could be a "nightmare", a councillor fears as local residents and businesses along the diversion route brace for the impact.
The five-mile stretch of the motorway between junctions 10 and 11 was closed in both directions at 9pm on Friday and will remain inaccessible until 6am on Monday while a bridge is demolished and a new gantry installed.
Concerns have been raised that thousands of drivers from Essex and other nearby counties will be stuck in gridlocked traffic over the weekend during the unprecedented closure.
It is the first planned daytime closure of the motorway - which encircles London - since it opened in 1986.
An 11.5-mile diversion route has been created to direct motorway traffic along A roads.
Daryl Jordan, of Woking Borough Council, told the PA news agency the Byfleet Road, which is close to junction 10, had been "chock-a-block" on Friday afternoon.
He said residents will be "affected massively".
"It is pulling people apart," the councillor told PA.
"I mean, you know, when you work full-time and then you're going to get home tonight from work thinking 'I must fill the fridge up' and you can't even get into your own village.
"It's going to be a nightmare.
"Just going down the road to get milk is going to be a problem tomorrow or picking up your dry cleaning."
Motoring experts are warning that official estimates of congestion levels may be "optimistic" while local councillors in areas where motorway traffic will be diverted are anticipating "gridlock".
The M25 normally carries between 4,000 and 6,000 vehicles in each direction every hour from 10am until 9pm at weekends between junctions nine and 11.
This includes many airline passengers travelling to, from and between 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 company believes its awareness campaign will help reduce traffic levels by approximately 50%, meaning the length of time added to journeys will be limited to around an hour.
It is urging drivers not to use their sat navs to attempt to find quicker alternative routes on minor roads due to fears this could cause major congestion.
Steve Gooding, director of motoring research charity the RAC Foundation, told PA:
"We must hope National Highways has overstated its dire predictions of sat navs 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."
Four more daytime closures of the M25 will take place up to September.
The project, due to be completed in summer 2025, will increase the number of lanes at junction 10, one of the UK's busiest and most dangerous motorway junctions.