Traffic had returned to normal by midday after a multiple vehicle crash closed lanes in both directions on the Sydney Harbour Bridge on Wednesday morning, causing long delays for commuters.

Five vehicles were involved in the crash, which occurred shortly before 6.45am on Wednesday, police said.

Three people were assessed on site by NSW Ambulance paramedics and were taken to hospital but none suffered life-threatening injuries.

One person was taken to St Vincent's Hospital in a serious condition and another was taken to the Royal North Shore Hospital in a stable condition, a spokesperson for Ambulance NSW said. 

. #harbourbridge crash has caused major traffic delays. Some north and southbound lanes closed pic.twitter.com/4TNqiMocrg — Andrew Denney (@Andrew_Denney) February 24, 2015

Police said a white Toyota van being driven south over the bridge swerved into a northbound lane and collided with a white panel van.

This crash pushed the panel van across three north-bound lanes, colliding with three further vehicles.

Four of the five northbound lanes were closed for 80 minutes while emergency services attended to the injured and cleared the road, police said.

Two southbound lanes were also closed.

Gridlocked traffic was also being experienced in east Sydney, with delays along Stanley Street.

By 10am, two hours after all lanes of the bridge had been reopened, citybound traffic was still queued along Victoria Road at Gladesvile and was moving slowly across the Gladesville Bridge.

The crash proved a major test for Sydney's transport system, with all approaching roads to the CBD affected, including the Lane Cove tunnel, Pacific Highway, Military Road, the Western Distributor, the M2, Victoria Road, and Epping Road.

Victoria Road, a notorious congestion hot-spot, was the last of the affected roads to return to normal.

It was still experiencing heavy traffic about 11am, before returning to normal by midday.

There was also widespread disruption to the city bus system, with hour-long delays on buses using Spit Road, Military Road, the City West Link, Victoria Road and the Anzac Bridge.

City-bound buses that normally travel across the Harbour Bridge terminated at North Sydney. Passengers were redirected on to trains to the city, which increased boarding and alighting times on the T1 North Shore & Northern Line.

Police were advising motorists to consider using trains or ferries or take an alternative route.

By 10am, heavy congestion had eased at train stations across the CBD and North Sydney.

The buses resumed their normal route over the bridge, but services were delayed for up to an hour.

Buses along the M2 also resumed their regular service but were delayed by up to 30 minutes. All services have since resumed their regular timetabling.

By midday, congestion across all affected roads and bus routes had returned to normal, following hour-long delays for much of the early morning. 

Sydney Trains is recognising all Sydney Buses tickets within the Sydney Metro area due to a road accident on the Sydney Harbour Bridge. — NSW TrainLink North (@TrainLinkNorth) February 24, 2015

It's days like this I really appreciate riding a bike to work. #SydneyTraffic #JustSayNoToCars #WestConnex pic.twitter.com/tFkwMPiqSV — James W.W. Rose (@jwwr) February 24, 2015

2 hours 15 mins for what is normally an hour trip #SydneyTraffic — bex (@defective_verb) February 24, 2015

 

- with Steve Jacobs