Drivers can expect delays and diversions on the roads today due to the London to Brighton Bike Ride.
Areas most affected include Tooting High Street in both directions due to large groups of cyclists on the A217 Tooting Broadway going across the junction on their way towards Croydon.
Tooting High Street is blocked for a couple of minutes at regular intervals.
There is also bad traffic on the A217 Southbound between Garratt Lane, Upper Tooting and the A236 Upper Green West, Mitcham.
Carshalton High Street is partly closed and drivers will be diverted along Park Lane.
There are restrictions on the Southern railway network for cyclists, who are not allowed on any Southern or Gatwick Express services from the first train until noon.
The ride, in its 39th year, sees thousands of cyclists ride the 54-mile route to the coast.