A crash which blocked northbound lanes of the Auckland Harbour Bridge is now clear.

Lanes 2 and 3 were blocked by the incident, which took place about 2.45pm, the NZ Transport Agency said.

Motorists should expect delays, with congestion through Spaghetti Junction likely, NZTA said.

An NZTA spokesperson said motorists could expect traffic to be back to normal around peak hour traffic.