Aucklanders are being invited to have their say on the design of a user-pays walking and cycling pathway across the harbour bridge.

The Getacross Campaign has commissioned architects Copeland Associates to design a tolled path to be tucked under the bridge's eastern clip-on, and wants guidance from the public on broad principles.

"We're after an iconic design with the wow factor - we want to create a top 10 tourist attraction for the Auckland region and an asset all Aucklanders will be proud of," said campaign spokesman Bevan Woodward.

"Hence we're inviting Aucklanders to have their say on the pathway's design."

He expected concept designs to emerge by the end of next month and to have the pathway ready for the Rugby World Cup, within a budget of about $15 million - most of which he hopes will be covered by tolls to repay private investment funds.

Copeland Associates director Barry Copeland said that although his firm had "quite a few ideas mulling around", the project would have high public visibility so it was important to encourage Aucklanders to become involved in the design.

He said innovative design thinking was needed "to allow access to New Zealand's most iconic bridge for all Aucklanders and visitors to our city".

"This is a waterfront project that ticks all the boxes for us - from an environmental, health, tourism and urban perspective it is a winner," Mr Copeland said.

Questions being asked of the public in an online survey on the campaign group's website include whether the pathway should be fully enclosed for shelter and whether there are any examples of walking and cycling bridges that might inspire the design.

Mr Woodward acknowledged yesterday that higher tolls than first suggested were being considered, in an effort to attract investors faced with a potentially shortened payback period.

The latest proposal is for $1.95 each way for users of a stored-value smart card, compared with an earlier suggestion of 95c, and for $4 for cash or eftpos transactions.

That is because of an indication from the Transport Agency that a new harbour crossing may be built within about 20 years, at which point the bridge would be made freely available to pedestrians and cyclists.

Transport Minister Steven Joyce has suggested a new crossing may be needed in 15 years.

Mr Woodward said that meant Getacross could guarantee potential investors a payback period of no more than 15 years. But he believed most commuters would hold stored-value cards, making it cheaper for them to cycle or walk across the bridge than to drive or catch buses or ferries.

He was also confident plenty of tourists would leap at the chance to cross the bridge for a $4 cash fee, given the spectacular views the pathway would offer.

Cycle Action Auckland, a part of the Getacross campaign, has meanwhile applied to the Ministry of Tourism for $80,000 from the $50 million Cycle Trail fund for a feasibility study and design work for the proposal.

The bridge scheme is part of a network of 12 Auckland rides the cycling group wants to plug into the national trail.

Mr Woodward said the feasibility study was needed to attract investors, but the campaign had decided to make a far more modest funding request than indicated earlier.

It is promoting the bridge pathway as offering "the world's best cycle ride in a city".