The Automobile Association says changing the speed limit is one thing but getting people to comply is another.

Public consultation starts today on Auckland Transport's proposal to drop a majority of speed limits in the city's centre from 50 kilometres an hour, to 30.

But the AA says it goes too far - and some roads should only fall to 40 kilometres an hour.

Spokesperson Barney Irvine told Mike Hosking getting people to comply with such a low speed is going to be difficult.

"The risk is that you're going to end up in a situation where you have low compliance and lots of tickets and that's just not a good road safety outcome."

He said the proposed speed is too slow and will cause more traffic congestion.

"Reduced speeds on the arterial roads will push even more people onto the heavily congested Southern Motorway and Northern Motorway."