Key Points:

Auckland transport politicians want a study of walking and cycling options across the Waitemata Harbour to consider a modestly-priced proposal to use the existing bridge at the cost of narrower traffic lanes.

Transit NZ confirmed yesterday that it had reached agreement with North Shore and Auckland cities, and Auckland Regional Council and its transport arm, to undertake a study after a proposal from lobbyists who say a cycleway on one side of the bridge and a walkway on the other could be built for less than $5 million.

Cycle Action Auckland says narrowing the bridge's clip-on traffic lanes from 3.5m to 3.1m - the same width as those on the main bridge - would allow 2.3m on each side for cyclists and pedestrians without having to add cantilevered structures which Transit estimates would cost about $40 million.

Transit regional manager Peter Spies acknowledged that motorway lanes were as narrow as 3.1m on Spaghetti Junction but said the study would have to determine whether that width was appropriate on the bridge's outside clip-on lanes, given their use by buses.

A committee resolution to support the new study said the exercise should include connections to local transport networks and give "specific consideration" to Cycle Action's proposal.