"A few bad eggs" are causing strife between motorists and cyclists along the Hutt Road cycleway in Wellington, with car owners discovering their side mirrors broken off and words scribbled across their bonnets.
Cyclists have been spotted riding past and knocking side mirrors off illegally parked cars, but people from nearby businesses believe it's only a small group of people causing trouble.
One man working along the stretch said he got into his car on Friday and realised a coach screw had been driven right into his tyre, but he was reluctant to assume it was deliberately done.
Tensions have been rising over the cars parked on the side of the shared footpath and cycleway, which Wellington City Council has yet to police.
Councillor Sarah Free said only a handful of cars were allowed to be parked there, as some people had been given informal permission from council while construction was happening on the road.
I think it's just a few bad eggs, eh. I think it's just a couple of angry dudes who have nowhere else to vent their anger.
The other cars should not be parked there, "but, you know, we haven't been particularly forward in policing it".
Council is planning to put up "no parking" signs within the next few weeks.
"We certainly don't condone or encourage anybody to damage anybody else's property," she said.
Chris Calvi-Freeman said it was "very unwise" for people to take matters into their own hands.
He said some drivers could apply for "encroachment licences" to park there, but those had to be renewed monthly.
The man who found a screw in his tyre said he had witnessed cyclists ride down the path and move closer to the cars to knock side mirrors off with their hands.
"I really don't think it's the majority of cyclists," he said. "Most cyclists are actually fairly grateful that they've had this kind of public spending spent on their hobby.
"I think it's just a few bad eggs, eh. I think it's just a couple of angry dudes who have nowhere else to vent their anger."
At least one other car had had the words "cycle lane" written across its bonnet in black marker, and photos were posted to Facebook.
The man said he was pleased to see other cyclists condemning the vandalism online.
Another worker said he had lost $50,000 in business over winter since the council began working on the road.
It's really counterproductive and unacceptable to damage someone's property. However, the city council has dropped the ball on this one.
"The cyclists have been given a lot and still aren't happy - thinking they have a right to now vandal and yell and curse in front of public, including children," he said.
People would come into the store or yell things such as "get off our f***ing cycleway" while riding past.
"[I've] tried to speak to them but it's hard to keep a straight face when approached by a man in lycra walking awkwardly in his cycle shoes sounding like Michael Flatley tap dancing."
Norm McIntyre, who also worked nearby, said side mirrors were constantly being knocked off the parked cars - he said there had been three such incidents just last week.
"It's not really an ideal place to be putting a cycle lane."
Cycling Action Network spokesman Patrick Morgan said "no one condones vandalism".
"It's really counterproductive and unacceptable to damage someone's property. However, the city council has dropped the ball on this one.
"They're not enforcing their own parking rules on a shared cycleway and footpath."
He said 400-500 people were cycling through the area each day, and it "gets pretty full at peak time". Having cars parked on the path could make it difficult when cyclists were also trying to dodge pedestrians.
"This is not a slow speed kind of waterfront shared path, it's a main commuting route.
"We've got one chance to get this right."