Motorists travelling from Manukau to Auckland city should allow up to an hour on the motorway this morning as a spilled load and accidents leave traffic moving along at a snail's pace.

New Zealand Transport Authority Auckland spokeswoman Sarah Azam says the knock-on effect from an earlier incident where a truck lost its load of plastic lunch boxes and drink bottles has resulted in the usual trip taking much longer than usual.

This has been compounded by a "myriad of issues" including accidents, breakdowns, school traffic and people returning to work after the holiday weekend.

Ms Azam says while the travel time along the Southern Motorway has improved from the 80-plus minutes it is still a lengthy trip.


"It's starting to pick up now but you'll still need to allow plenty of time for your journey," she says.

The latest incident adding to this morning's headache commute was a multi-car crash near Papakura.

The traffic agency warned people to exercise patience."

Multi-car #crash on Sthn Mwy prior to Papakura will cause further delays for citybound motorists. Both lanes open. Pls #BePatient "

Ms Azam says the knock-on effect from the first incident, which happened before 6am this morning, is still being felt hours later.

"There has been a myriad of issues. It kicked off with someone losing a load of plastic bottles and lunch boxes followed by quite a few accidents and breakdowns which have all converged to make it very slow going this morning," she says.

The unsecured load which triggered today's disruption was spread across three lanes and stretched 150m along the motorway. Road sweepers were needed to clear the debris.

Police said a section of the Southern Motorway just before Greenlane was down to one lane as motorists picked their way through smashed glass and debris.

9:45AM FINAL UPDATE:Southern Motorway traffic remains heavy citybound prior to Papakura - and between Manukau to Greenlane - but it is starting to ease. Please be extra patient today.------8:45AM UPDATE:A multi-car crash prior to Papakura will add to the delays for motorists on the Southern Motorway today. Please be patient. Two lanes remain open but traffic must slow for safety.------7:45AM UPDATEThe Southern Motorway remains very slow into Auckland city this morning. Traffic is congested Drury to Takanini and again from Manukau to Greenlane. Please allow plenty of extra time for your journey today.------6:25AM 09FEB - DEBRIS - SOUTHERN MWY, GREENLANEA load of plastic bottles has spilled onto the Southern Motorway citybound lanes prior to the Greenlane interchange. NZ Police have managed to roughly clear the Mwy to enable lanes to be reopened however traffic is moving VERY slowly through the area and the left lane remains closed. Traffic is congested back to Mt Wellington. Please expect a slow journey into the city this morning. ^TP

Posted by NZ Transport Agency - Auckland & Northland on Monday, February 8, 2016

The New Zealand Transport Authority posted a tweet warning motorists the journey to town was exceptionally slow because of the spill.

"A load of debris has partially blocked the Sthn Mwy citybound prior to Greenlane. 3 lanes are open but traffic is VERY slow here."

Police were also trying to find the truck that had lost its load.

To add to the traffic woes there was a breakdown blocking the left lane city-bound at the Ellerslie on-ramp, just before the spill.

Ms Azam says traffic is starting to pick up now but people still need to allow up to an hour to make the trip along the Southern Motorway into the city.