Dramatic video shows the moment a car burst into flames on Auckland’s Northwestern Motorway this afternoon.

A car on fire on SH16 initially left two westbound lanes blocked, with motorists facing lengthy delays.

The blockage was just after St Lukes Rd.

The New Zealand Transport Agency says motorists should expect delays.

Traffic banking up on Auckland's Northwestern Motorway after a car fire this afternoon. Photo / Supplied

Drivers have also been urged to pass the site with care.

The lanes were re-opened around 3.30pm.

Delays are also facing motorists using the Southern Motorway this afternoon.

A crash near Manurewa has resulted in a backlog.

While the impacted vehicles are now clear of the lanes, traffic is slow.