London police and the city have shut down the Stoney Creek bridge on Windermere Road, west of Adelaide.
The move came promptly on Wednesday after police, city staff and contractors responsible for the bridge project determined it is no longer safe to allow any through traffic on the bridge as motorists are disobeying signs.
Police are also warning of issuing fines to drivers who disobey road closures.
The fine for violating the bylaw is $180 and police say motorists can expect to see them patrolling the area on a regular basis.
In a news release, police say they are disturbed by the behaviour of some motorists, "...who blatantly choose to disregard the closure putting all other road users including cyclists and pedestrians as well as construction workers at an incredible risk."
The only time frame on the closure from officials is that it will be closed for several months for repairs to the bridge.
