Auckland motorists are inching towards congestion charges.

According to a joint Auckland Council-government report, the Congestion Question, charging motorists shows real promise to help throttle back the use of the city's increasingly clogged roads.

The parties have accepted the report's recommendations to look further into how it might work, and pricing.

By August, the researchers hope to have identified, designed and assessed how much and where motorists could be charged.

No ball-park figures were mentioned in the report but automatic number plate reading was likely to be the best way to charge people.

The authors say congestion is now spreading throughout Auckland's day - 33 percent more of main roads are now congested than in 2014.

That meant increasing travel times, unreliability with people now needing to add up to 55 percent more time to their journey to get there on time, and ultimately cost.

There are more than 700 new cars on Auckland's roads every week.