Commuters are facing a torrid journey home on Wednesday night, with motorists warned to avoid the Sydney CBD while a marriage equality march takes place down Oxford Street.
Large crowds are expected to congregate at Taylor Square in Darlinghurst for the Result Night Street Festival for Marriage Equality before marching at 7pm along Oxford Street, College Street and Prince Albert Road to Hyde Park.
A spokeswoman for the Transport Management Centre said road closures included parts of Oxford Street, College Street and Prince Albert Road.
Streets adjacent to the march route that may also be affected include Crown Street, Flinders Street, Liverpool Street, Wentworth Avenue and William Street.
The road closures will also force some buses to be diverted, with passengers advised to allow extra travel time.
Motorists in western Sydney have also been advised to expect heavy traffic as an estimated 70,000 fans flock to Sydney Olympic Park for the World Cup Qualifier match between the Socceroos and Honduras at ANZ Stadium.