A handful of controversial T3 lane cameras installed along one of Auckland's busiest stretches of road have been vandalised and smashed - and the vandals may have been caught on video.

For months, North Shore residents have been up in arms about 68 new T3 cameras on Onewa Rd, which they say are a hazard for pedestrians.

The cameras, which cover just a 2.3km stretch of road have been switched on for a week, but are operating in a warning capacity, which an Auckland Transport spokesperson said would tell drivers that they had infringed without issuing a fine.

Previously, Auckland Transport staff had to stand on the roadside in all weather to catch rulebreakers.

But since being in operation, one local told the Herald at least three cameras have been smashed.

"So it starts. I saw three cameras in a row that had the casing smashed down the bottom of Onewa Rd.

"It's very unpopular, and costs the taxpayer heaps."

Auckland Transport said they were checking all cameras on the road for damage but revealed that another camera would identify those responsible. That video has already been sent to police.

The AT spokesperson told the Herald that repair costs will be "considerable" and they would seek "total cost recovery" from those found responsible.

The police have been approached for comment.

Photos of the damage were shared to social media. Photo / Supplied

The 68 cameras were placed in 17 transit zones - nine towards the city and eight towards Birkenhead – which can only be used by cars with three or more people between 6.30am-10am and 4pm-6pm, Monday to Friday.

Residents took to Facebook to vent their frustration at the cameras and say they're not surprised vandals have taken to them.

"Good job. Can't believe the council think those cameras are a good idea," one person wrote.

Another said: "I hope these ongoing repair costs come out of your [AT's] pockets and not the taxpayer for what is/was a revenue collecting idea from the start. The money spent could have been used in far better ways to resolve the traffic problems on Onewa Rd."

AT counters that any motorists travelling illegally in the T3 lane slow the network down and hampers their efforts to reach emission targets.

"Having officers travel to and from enforcement zones to collect footage, return to base to review footage and then in a vehicle back out on-street to complete the pm capture would just add to congestion and emissions," they argued.

The road, which is the main access to the Harbour Bridge for residents of Northcote, Birkenhead and surrounding suburbs, has long been plagued by slow commuter traffic.

A transit lane in some form has been operational on Onewa Rd since 1982 but was first strictly enforced in 2002, limiting one lane to public transport and high-occupancy vehicles.

Since then it has become a strict T3 lane in both directions during peak commuter times with AT vigilantly enforcing the rules and issuing tickets.

Last year, Kaipātiki Local Board chairman John Gillon said enforcement was needed but he was "shocked at the size of the hammer they are using to crack this nut".

He said that residents of Onewa Rd who had a genuine need to move in and out of the T3 lane would be negatively affected by the camera network, citing the case of an elderly resident who was already apprehensive about leaving her home after being ticketed for being in the transit lane after pulling out of her driveway.

But that's not the only gripe from the North Shore community about the new T3 lane cameras.

Concerns have been raised about the poles for the cameras, which some locals say block the path, and their installation has been described as "incompetent" by a local politician.

"The location of these poles in the middle of the footpath is dangerous to sight-impaired people and massively inconvenient to walkers - the people for whom the footpaths are actually intended," one local wrote on Facebook.

Other residents pointed out the posts presented a hazard for those using mobility scooters and parents pushing twin prams.

Multiple residents described the layout as "crazy" while others said "this looks like a third-world country result" and described the poles as a "giant middle finger to the community".

Auckland Transport told the Herald they still back the cameras, saying that the organisation is "committed to delivering high performing networks to enable efficient travel times for road users".

"These transit lanes are one of the ways we can make travel times quicker, reduce emissions and provide more sustainable ways for people to travel around Tāmaki Makaurau/Auckland," they said.

"It's disappointing to see vandalism of any kind, let alone vandalism which ends up costing ratepayers and road users alike."