Commuters are facing three months of utter chaos after a surprise announcement that Holloway Road will be closed for £25million works.

The Upper Holloway bridge is being replaced so the Gospel Oak to Barking London Overground line can be electrified – a project that has already closed the station until February.

The work has caused problems since it began in 2014 and the latest disruption will leave drivers, cyclists and bus users all being diverted along Tufnell Park Road and Junction Road when work starts a week on Friday.

Work will take place between Fairbridge Road and Wedmore Gardens. Pedestrians won’t be affected.

The bridge will be replaced over Christmas, but before then all the utilities running beneath the road surface need to be transferred to another specially-made bridge, which is being built to ensure the road itself can stay open more.

The new utilities bridge was built in June but cables and pipes could not be moved across due to their “complex layout, poor condition and a leaking water main”.

Nick Fairholme, TfL’s director of surface transport works, said: “The vital work to replace the Upper Holloway Bridge with a strong, future-proofed and durable structure now requires complex rerouting of the utilities.

“To safely complete this complicated work we need a series of closures of the A1 and we are sorry for the disruption this will cause to road journeys in the area.

“We are doing everything we can to minimise disruption and complete the works as quickly as possible. We are committed to helping drivers, local businesses and local residents plan their journeys to help avoid the worst of the disruption and apologise for delays caused during this vital work.”

Bus routes 17, 43, 263, 271 and N41 will all be affected.

TfL said work at Archway and Highbury Corner is being “re-planned” and is working with surrounding boroughs to cancel all non-emergency roadworks over the period.

Letters and emails are being sent to all neighbours, businesses and road users and road users will be able to plan their diverted journey at tfl.gov.uk/upper-holloway-bridge.

The road will be closed to all southbound traffic from October 21 until January 16, in addition to which it will be closed northbound between October 21 and October 31; over the weekend of November 18 to 21; over the weekend of November 25 to 28; and from Christmas Eve until the end of the project.