It connects Coombe Lane West in New Malden to Coombe Road in Raynes Park.
Bridge safety maintenance is being undertaken by Transport for London every weekend until the 17th of November.
Listeners have reported missing hospital appointments and family events and have questioned why the works cannot be done overnight.
TfL says failure to carry out this work now could result in the road being completely closed to traffic in the future.
Although some drivers have reported leaving two hours ahead of their journeys, TfL is still urging them to “plan ahead.”
A TfL spokesperson said: “We’re carrying out safety critical maintenance work to the A3 Coombe Lane Flyover to ensure that this vital piece of infrastructure can continue to serve people living in the area for years to come. Failure to carry out this work now could result in the road being completely closed to traffic in the future.
“We carefully assessed several options for carrying out the work while minimising disruption as much as possible and weekend closures are the most effective way of carrying out this vital work. We’re sorry for the disruption caused and will continue to monitor roads in the area during each closure but would also encourage people to plan ahead for their journeys.”
