A controversial scheme to introduce a set of traffic lights at a busy junction will begin on Monday.

A road closure will be in place at one end of Harper Lane, near Radlett, for more than four months.

The closure will be in place from August 3 at the Watling Street end of Harper Lane and it will last until December 17.

There will also be temporary traffic lights in Watling Street in some weeks, which brings the potential for traffic delays in the area.

The traffic lights were meant to be introduced at the beginning of 2019 but Hertfordshire County Council paused the scheme following a backlash and a petition signed by 1,000 residents, after traffic built up immediately when roadworks were first put in place.

When a development of 206 homes was approved in Harper Lane by St Albans District Council, it was agreed that developer Bloor Homes had to introduce traffic lights at the junction of Harper Lane and Watling Street.

It is because a new footpath and cycle path is being created along Harper Lane, which will force the narrow bridge at the end of the road to become single file.

An option to widen the railway bridge in Harper Lane is “too expensive”, according to the report from a meeting involving members of the county council's highways panel.

The Harperbury development has since sprung up in Harper Lane with residents already moving into their new homes.

St Albans & Harpenden Review:

A new roundabout has been constructed in Harper Lane at the Harperbury development

Now after a delay of more than a year, the traffic light scheme will finally be starting but it will be done differently to last time.

When the work began in 2019, Harper Lane remained open with temporary three-way traffic lights, which caused major delays.

This time, the work will be carried out in three phases, and the Radlett end of Harper Lane will be shut for the entire duration of the roadworks, so across all three phases.

Phase A, which will run from August 3 until August 21 will see temporary two-way traffic lights in Watling Street, although Bloor Homes says the lights will only be switched on during rush hour.

Phase A will see white lines and traffic islands removed.

Phase B, which runs from August 24 until December 4 will see the traffic lights removed and a reduced speed put in place in Watling Street.

There may be occasions where traffic lights are reintroduced temporarily.

This phase will see permanent traffic lights installed, new traffic islands and railings, and carriageway widening.

St Albans & Harpenden Review:

This bridge will become single file. Credit: Google Street View

St Albans & Harpenden Review:

A permanent traffic light will be placed somewhere around here for drivers wanting to use the railway bridge. There will also be permanent lights in Watling Street Credit: Google Street View

The final phase, Phase C, which will run from December 7 until December 17, will see the road surface completed, and allow for a safety audit to be carried out.

Speed will still be reduced and there is the potential for two-way traffic lights.

By December 17, it is expected the new junction will be completed, with new permanent traffic lights, and the road closure in Harper Lane will be lifted.

While Harper Lane is closed, a very long diversion route has been drawn up by the county council.

It involves taking drivers via the A414 near Park Street, Napsbury and London Colney, through Shenley, via Borehamwood town centre, Allum Lane via Elstree, and then Watling Street into Radlett.

St Albans & Harpenden Review:

This is the official diversion that has been drawn up. Credit: Bloor Homes

St Albans & Harpenden Review:

The junction of Watling Street and Harper Lane. Credit: Google Street View

However, most drivers will be able to use Radlett Lane and Shenley Hill between Radlett and Shenley, although this route will be busy.

Due to a weak bridge, vehicles over 7.5 tonnes cannot use Shenley Hill.

Once the new junction is completed, the county council will reportedly “monitor” the new junction to see what impact it has on the flow of traffic.

Bloor Homes says it apologises for “inconvenience these necessary works may cause”, adding it has worked with the county council to developed a traffic management strategy that will “maintain traffic flows” on Watling Street in both directions for the majority of the works.