Buses, trucks and luxury SUVs will be among a list of wide-bodied vehicles no longer able to comfortably fit within the kerbside lanes of Tamaki Drive courtesy of a new $14 million cycleway.

Roadworks on one of Auckland's busiest roads travelling east out of Auckland city centre along the waterfront, Tamaki Dr, have caused a major traffic choke point since February this year.

And it seems the strain on road vehicles is set to continue once the $14m project is complete next year.

Internal Auckland Transport (AT) correspondence and designs say buses will be required to use the middle lanes of Tamaki Dr, because the kerbside lanes are too narrow at 2.95 metres.

Graphics within an AT report have specifically placed buses in the middle lane of the arterial Tamaki Drive route because that is where they are expected to travel once construction is complete.

How the buses are to pick up passengers from the middle lanes, and whether they will hold up traffic when doing so, is unclear.

Artist's impression of new Tamaki Drive cycleway. Source / Auckland Transport

In response to the Herald, AT claimed "A bus is 2.5 metres wide so there is adequate room for them to operate safely".

But in AT's own Code of Practice document it states "Currently a body width of up to 2.5m can be built but it needs to be remembered that in reality most buses are 2.85m wide including mirror widths. This latter measurement should be reflected in any designs of bus related infrastructure."

This would leave 5 centimetres either side of a typical Auckland bus in the outside lanes of Tamaki Dr to drive and park to pick up passengers.

AT told the Herald there had been substantial research by AT's road safety team and chief engineer into the safety of the road corridor - which was also ticked off by an independent safety auditor.

"We have done vehicle surveys on the road including video monitoring over a seven-day period. This confirmed that heavy commercial vehicles generally use the middle two lanes," an AT spokesperson said.

"At no time during the survey period was there a situation where four large vehicles, either buses or trucks, were side by side.

"The purpose behind the design for Tamaki Drive that Auckland Transport is currently delivering, is to ensure that heavy commercial vehicles have most of the road space allocated to them through the slightly wider middle lanes, while also maintaining the safety of smaller vehicles."

Auckland Councillor Desley Simpson who represents the Orakei Ward which Tamaki Dr leads into said she had been informed by AT that if the road corridor was narrower than designs had specified, it would be fixed.

"I'm no engineer but when you look at the naked eye I certainly understand how people can be concerned that four lanes won't fit currently," Simpson said.

"But I also appreciated that the job isn't finished and AT are giving me consistent assurance that it will be four lanes and that the contractor is building to the design specifications that AT have given them.

"AT told me if those specifications are wrong they will be changed."

Construction on the Estuary Bridge as part of AT's Tamaki Dr cyclelane construction. Source: Youtube / Auckland Transport

Public Transport Users Association NZ national coordinator, Jon Reeves, said new cycle lanes across Auckland are increasingly becoming a hazard for bus users.

"The lane space has been taken for wider bike paths and so it seems like what we've noticed is there's been a real push on cycleways at the expense of decent public transport paths, like in this case the lanes for buses," Reeves said.

"The buses now have to get across to the centre lane which is going to be an inconvenience for the bus driver but it's also potentially may end up becoming a bit of a risk to other motorists. Is it making sense? Who in AT is signing these things off?

"Did AT do public consultation on the width of these lanes and say to the public from the outset 'hey buses are going to have to try and squeeze across a lane to travel safely down the middle lane."

However, AT maintained that similar four-lane corridors exist in Auckland where buses travel.

"Karangahape Road before the upgrade, had double decker buses and heavy vehicles operating without issue in lanes less than three metres wide," an AT spokesperson said.

"Another is example is New North Road in Kingsland, which in peak time has four traffic lanes on a road 11.5 metres wide.

"AT stands by the assessment that there is sufficient width in each direction across the four lanes to accommodate a bus and truck tracking side by side. There is also enough width in the lanes for large vehicles, such as SUVs, that are towing boat trailers."