New data obtained by Highways shows the impact of National Highways' £317m M25 Junction 10 scheme, with vehicles delayed by nearly a quarter of a million hours in just one month.
The data provided by National Highways under the Freedom of Information Act shows that vehicles were delayed by more than a million hours in the last six months of 2023, reaching a peak of 230,606 vehicle hours in September.
Over the year, vehicles passing through the works were delayed by a total of 1.77 million hours.
The government-owned company produces the data for its performance indicator (PI) 2.5, which ‘measures the additional journey time during roadworks for all vehicle types, compared to an average benchmark journey time measured before the roadworks were in place’.
The delays are therefore in addition to the ‘large queues and heavy congestion on a daily basis’ that National Highways has given as the reason for the works, at one of the busiest junctions in the country.
Preparation work for the scheme started in late 2022, with the first traffic management introduced in December and the main work starting in early 2023.
Source: National Highways
The data also shows that delays rose from an average of 6.4 seconds per mile in September 2022 to a peak of 31.8 seconds per mile a year later, before falling back to 24.6 seconds at the end of last year.
Other data obtained by Highways show that the number of vehicles delayed by at least 30 seconds per mile rose from around 8% at the beginning of 2023 to nearly 30% over three months last summer.
Similarly, the number delayed by 60 seconds or more rose fivefold from 4% in January 2023 to more than 20% in September.
Source: National Highways
National Highways said the summer peak reflects the introduction of traffic management on the sensitive slip roads leading on and off Junction 10. It added that it expects this impact to be relieved in spring 2024 when the new lanes open.
However, the data released under FOI only covers vehicles on various sections of the main carriageways of the M25 and A3 and therefore does not appear to include vehicles using the junction to change from one road to the other.
A traffic management plan drawn up before the project started shows that, for example, the works were expected to add 516 seconds (eight and a half minutes) to average journeys for vehicles using the junction in the morning to change from the M25 eastbound (clockwise) to the northbound A3.
As well as routine delays for road users driving through the scheme, there have been a number of road closures, particularly in relation to the installation of new bridges, and more are planned for this year.
Simon Elliott, programme manager on the scheme, said: ‘This is a major scheme on one of the busiest junctions and we understand the impact of this work.
‘We aim to give motorists as much notice as possible, so they are able to plan their journeys well in advance.’
