One of the main roads through Cheam is gridlocked after two major events coincided.
Traffic is at a standstill on Ewell Road after an open day at Nonsuch High School for Girls and a concert in the park were arranged on the same evening.
Motorists are advised to avoid the area.
One neighbour said: "It's at a standstill from the school to the lights. We have to deal with this at school leaving time but to put up with it now is a real pain."