Huge lorries are being forced to reverse down tight residential streets after new traffic calming measures blocked a through route.
Posts have been installed on either side of a stretch of Ashcombe Road, Wimbledon, to stop heavy good vehicles travelling to Queens Road and on to the Broadway.
A weight restriction failed to stop drivers using the route as a short-cut to the Broadway despite the 7.5-tonne ban introduced in 2011.
A public consultation by Merton Council last year heard residents’ complaints about noise made by lorries when they clunked over the speed bumps.
People in neighbouring roads have now said new traffic calming measures, finished on March 31, mean lorries are travelling over the railway bridge, seeing the posts and then reversing back over the bridge.
Residents said drivers then detour down Cromwell Road and Haydon Park Road, which already suffer from traffic congestion.
Juliet Johnston, of Haydon Park Road, said: “It is causing havoc.
"They get as far as the posts and realise they can’t get through and they reverse back over the bridge. It’s dangerous.”
The lorry ban details a 7.5-tonne weight restriction on the road, with the exception of refuse lorries and those loading in the affected roads.
Width restriction warning signs have now been installed at the junction of Gap Road and Ashcombe Road, and on Ashcombe Road between Haydon Park Road and Cromwell Road.
Councillor Andrew Judge said: “We have a lorry ban, but it is very difficult to enforce without physical measures.
“There is a lot of noise in the early hours of the morning.
“We want to deter rat running and enforce the lorry ban.
" It is a residential area and it is inappropriate to take large vehicles through.”