An elevated cycling freeway will be built above Footscray Road, transporting cyclists faster into Melbourne's CBD.

The 2.5-kilometre "veloway" will sit underneath a future road flyover over Footscray Road and is designed for serious commuters, bypassing a number of traffic lights.

It will have escape hatches and stairs, so that people can exit it if they get into an accident or have a puncture.

"[It's very much] a freeway for people riding their bikes each day in and out of the city," Roads Minister Luke Donnellan said.