NSW govt justifies Mad Max road closure

A government agency has attempted to justify closing a major road in Sydney's CBD for three hours, saying a parade of vehicles from the Mad Max movie franchise will draw more tourists to the city.

The 10am-1pm closure of the Cahill Expressway, which connects the CBD to the Harbour Bridge, caused heavy traffic in the city on Wednesday.

Transport for NSW says it approved the closure without charge because of the "significant broader benefits" to Sydney and NSW.

"Hosting significant events such as this is part and parcel of the global city status that Sydney enjoys," an official said.

"The event was timed to take place outside the morning peak to reduce its impact on motorists and bus customers."

The aptly-named Mad Max: Fury Road, starring Tom Hardy and Charlize Theron, opens in Australian cinemas on Thursday.