Heavy traffic on the Southwestern Motorway and Northwestern Motorway is causing delays this morning and a citybound crash on the Southern Motorway is adding to driver woes.

The New Zealand Transport Agency said the crash near the onramp of the Southeastern Highway is blocking the right lane.

The NZTA said traffic on the Southwestern Motorway from Puhinui Rd to Onehunga was very heavy and for motorists to expect delays and the Northwestern Motorway was heavy between Lincoln Road and Patiki Road.

Earlier crashes and breakdowns on the Northwestern and Southern Motorways have now been cleared, but congestion remains from Highbrook to Penrose.