Motoring mayhem will hit drivers travelling along the A414 North Orbital later this month as lane closures take place between the Park Street and London Colney roundabouts – for 16 weeks.

With major disruption looming for drivers, concerns have been expressed to the county council (HCC) by district councillor for Colney Heath, Chris Brazier.

Repair work is to be carried out on the corroding Napsbury Lane bridge, which crosses the A414 near Aylett Nurseries, between both roundabouts.

That will result in the dual carriageway being reduced to a one-carriageway road.

Preparation work for the £500,000 scheme will start on Saturday, July 25, with a full night-time closure of both east and westbound carriageways.

Then, from Sunday July 26, there will be a 24-hour lane closure - lane two - for 16 weeks on the A414 in both directions, between the Park Street and London Colney roundabouts.

There will also be road closures on Napsbury Lane (B5378) for part of the time.

Cllr Brazier has written to Cllr Terry Douris, the county council’s cabinet member for highways, saying: “As you know, the A414 is a major link road between the M25, A1(M) and the M1. By reducing this road during the day time will cause major traffic problems to the surrounding area.

“If the work is scheduled for the daytime, in my opinion you would increase traffic accidents and [there will be] long delays for residents, lorries and buses travelling along the route.

“Could I suggest the work is carried out at night and not during the day; bridge repairs are essential but traffic safety is also essential.”

The Herts Advertiser understands that work on the bridge will involve a shuttered working area, to protect working contractors and passing traffic.

This protective cage will encroach onto the outside carriageways and it is neither practical nor feasible to remove it on a daily basis.

Cllr Douris said: “While there is never a good time to do works of this nature, the bridge will soon be coming to a point where its safety might be compromised, and we have a duty to make sure that all road users are safe.

“We’ve arranged for the start of this £500,000 scheme to take place during the school holidays to help lessen traffic delays for people as much as possible.”

Road users are advised to avoid this section of the A414, plan ahead and allow extra time for their journeys.