Traffic chaos in Melbourne following West Gate Freeway crash

A serious car accident which forced all outbound lanes of Melbourne's West Gate Freeway to close has caused traffic delays across the city.

All lanes are now open but delays remain citybound on the Monash Freeway and on surrounding roads.

Ambulance Victoria confirmed three people - two men and a woman - were taken to the Royal Melbourne Hospital.

Paramedics were called to the site about 10.45am, with police and fire crews also attending the scene.

Drivers have been advised to avoid all outbound lanes of the freeway and to exit the Domain Tunnel at Kings Way and detour via South Melbourne.

The crash follows an incident overnight that resulted in one man being taken to hospital in a critical condition after he and another car were seen "racing" on the Monash Freeway.

The other driver fled the scene and police have urged them to come forward.