Key Points:

An extra 40 cars a day - close to 300 cars a week - are now travelling on Auckland's roads as peak hour extends to almost seven hours a day in an increasingly gridlocked system.

On the motorways, traffic growth had steadied in recent years as the state highways reached full capacity, but traffic planners expect daily numbers of cars to lift as new motorway projects, such as the Victoria Park tunnel, are completed.

Peak-hour traffic, which was once confined to 1.5 hours from 7.30am and after 5pm, has now increased to seven hours a day in Auckland and is now considered to be any time between 6.30am to 9.30am, beginning again as early as 3.30pm.

Commuters were starting and finishing work earlier in a bid to beat the rush, particularly over the short winter days.

That combined with parents picking up children from school meant commuters could expect to be stuck in traffic from mid-afternoon until 7pm, said Joseph Flanagan, Transit's Auckland network manager.

"Auckland is a growing city, there's something like an extra 40 cars on the road each day.

"Peak hours, where the traffic speed is impinged, have started earlier year on year, but have not extended later."

Recently completed projects like the Central Motorway Junction - also known as Spaghetti Junction - would increase the number of cars able to travel on the motorway, Flanagan said.

However, the full effect would not be seen until other pieces of the Transit puzzle, such as the VictoriaPark tunnel and Western Ring Route, were completed.

Building more roads was not the solution to Auckland's traffic woes, said Flanagan.

A mix of strategies, such as cameras - to monitor and detour traffic to other routes, or encourage lane changes - and ramp signals were improving traffic flow, he said. Transit was committed to providing a public transport system and Flanagan pointed to the North Shore's northern busway as proof of that success.

Just 18 months old, the express bus between the North Shore and Auckland was taking 400 cars off the roads at peak hour every day, said Flanagan.

Matthew Rednall, Auckland City Council's road manager, said most of the council's main arterial routes had a traffic increase of between 1 and 3 per cent each year.

Most were nearly at full capacity and a further 200,000 cars were waiting to roll on to Auckland roads.

"If they drive in peak hour to get to work, then yes, that growth is unsustainable," he said.

Motorists needed to think about when to drive, particularly in peak hours, and were encouraged to car pool, use alternative routes, travel off-peak, walk or use public transport.

Local authorities were working with the Auckland Regional Transport Authority to introduce an integrated ticket for buses, trains and ferries and rail services were about to be improved with electrification.

Tips to beat the traffic

* Drive in off-peak hours if possible
* Peak hours begin earlier, so leave home later if possible
* Do supermarket shopping at night
* Car-pool to work
* Try an alternative route
* Walk or use public transport