Using a satnav to get around M25 closure will ‘cause gridlock’

Drivers are being urged to ignore satnavs and only follow official diversion routes to prevent gridlock during an “unprecedented” closure of the M25 this weekend. National Highways issued the alert as it prepares to close a five-mile stretch of the motorway in Surrey [1] between 9pm on Friday and 6am on Monday. It will be the first scheduled daytime all-lanes shutdown on the M25 [2] since it opened in 1986.

A footbridge is being demolished and a new gantry for overhead signs will be installed at the junctionCredit: GARETH FULLER/PA

The government-owned company, which runs England’s roads, estimates that drivers who follow signs for diversion routes on A-roads [3] will have an hour added to their usual journey times between junctions 10 and 11, which will be shut in both directions.

Traffic will be diverted via Cobham, Byfleet, West Byfleet and Sheerwater before rejoining the motorway at Chertsey, just south of its Heathrow Airport [4] stretch. There are fears that some motorists may try to find unofficial alternative routes via minor roads, however. Jonathan Wade, project lead at National Highways [5], said: “How many people are going to take the initiative and try and use satnavs?

“There’s probably a greater risk of congestion by people just doing their own thing and thinking they can perhaps beat the signs and find a shorter or quicker route. “That will cause further congestion on some of the key junctions so please avoid doing that if at all possible.”

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Modelling carried out by National Highways estimated that drivers would face delays of up to five hours without mitigation measures, such as urging motorists to stay away from the area and creating official diversion routes. Satnavs will not be automatically updated with the official M25 diversion route, however.

Earlier this year, the Government announced that traffic regulation orders (TROs) will be digitised [6] so satnavs can include their details. TROs are the legal orders authorising the closure of highways for roadworks to be carried out. A draft law to digitise and standardise TROs is currently before Parliament.

Instead, drivers are being encouraged to follow diversion signs on the roads. Daniel Kittredge, a senior project manager at National Highways, said: “If people move away from diversion routes that we prescribe, it creates additional issues in different parts of the road network. “The majority of the time that will be local roads [7], so that really impacts residents in those particular areas.

That’s why we’re trying to encourage people to not follow the satnav. “Stick on the prescribed diversion route. It’s going to be more suitable for your journey.”

Drivers are being warned to avoid the area if possible during the closure. National Highways said the closure is necessary so a footbridge can be demolished and a new gantry for overhead signs can be installed.

‘Only travel if necessary’

The company believes only about an hour will be added to journeys because of the steps it has taken, which is based on a halving in normal traffic flow of between 4,000 and 6,000 vehicles an hour. But Mr Wade said that predicting how many drivers will want to navigate the area during the first full weekend closure of the M25 will be tricky, adding: “Because it’s so unprecedented, we’ve got nothing to benchmark it against.

“There’s never been a closure of this nature. We really can’t be certain how many people will heed the messages which we’ve given. “It’s very difficult to determine right now how effective all our traffic management will be.

Please don’t travel if you can avoid it.”

Four more daytime closures of the M25 stretch between junctions 10 and 11 will take place up to September.

The project, scheduled to be completed in the summer of 2025, will increase the number of lanes and make it easier to enter and exit the M25 at junction 10, which is one of the UK’s busiest and most dangerous motorway junctions.

References

^ Surrey (www.telegraph.co.uk)
^ all-lanes shutdown on the M25 (www.telegraph.co.uk)
^ A-roads (www.telegraph.co.uk)
^ Heathrow Airport (www.telegraph.co.uk)
^ National Highways (www.telegraph.co.uk)
^ will be digitised (www.telegraph.co.uk)
^ local roads (www.telegraph.co.uk)