Surrey County Council has provided further background on its decision to close a large section of Reigate Hill southbound from Monday 7 September and to prohibit access to Gatton Bottom.
During the closure, which could last up to 14 weeks, repairs will be carried out to a retaining wall and the vehicle barrier that sits upon it.
The southbound side of the road will be shut 24 hours a day from the M25 Junction 8 roundabout down to a point above the petrol station and pub.
The county council has ruled out temporary traffic lights because they would mean the work could only be done in shorter sections and would take longer.
Only working at night would also not help because the road will have to be closed anyway for the duration of the project, the council has said.
Access to Gatton Bottom will be closed from the A217 because of worries about enforcing the 7.5 tonne limit on that road, and the potential for a dangerous back-up on to the M25 as drivers decide if their vehicle is suitable.
An official diversion route that has been published is just over 20 miles long, heading north from Junction 8 and taking in parts of Burgh Heath, Epsom, Ashtead, Leatherhead and Dorking before a return along the A25.
Surrey County Council has said that the route has been selected as being on equivalent A roads that all vehicles can manage.
The council says it expects local drivers will find other routes, and will install signs on some local roads saying that they are unsuitable for HGVs.
Buses will be diverted via Pebble Hill Road.
The council has said that it will work with the contractor to accelerate the works as much as possible.
During the closure, the Reigate Hill café will be accessible via Wray Lane and Gatton Bottom.
The work is not being combined with the upgrade of Junction 8 and the top of Reigate Hill that is scheduled for April 2021, essentially because the council is not confident enough that Highways England will begin those works at that time.
More details on the project are below.
Cover / social media image of road sign credit istock.com