Key Points:

Boyracers descended on Christchurch at the weekend, throwing bottles at police and angering local hotel owners to the extent some are considering leaving the city.

The boyracers were in the city to attend the annual 4s and Rotary car show at Westpac Stadium - a car convention for young people.

Canterbury road policing group senior sergeant Trevor Pullen said most of the car enthusiasts were well behaved, but some seemed intent on causing disruption.

An irresponsible few decided to pour diesel on the road on Harper Avenue in Christchurch, he said.

Mr Pullen said bottles were thrown at police and the road side was littered with broken glass, empty cans and beer bottles.

One officer was hit three times by flying bottles, however no police had injuries requiring medical attention.

Christchurch Mayor Bob Parker last week introduced new measures to target boyracers ahead of the weekend car show - closing Oxford Terrace to all traffic from 10pm to 5am, and banning parking in Moorhouse Ave.

But city hotel and motel owners said the ban just shifted the problem to other streets.

They said they boyracers made their lives unbearable and they were afraid to complain to police for fear of retaliation.

One motel owner who did not want to be named told Radio New Zealand this weekend was the worst he had experienced in the five years he had been operating in the city.

Some of his guests had said they would never return to Christchurch, or New Zealand, and he too was thinking of leaving.

"The sooner we can get out of Christchurch the better. We've had enough and we're not the only ones. It's affecting our bottom line, it's affecting our health and it's just so unpleasant."

Mr Parker said the council was considering widening the ban next year, but was not sure what long-term effect it would have.

"We can't put a ban over the entire city. We are treating the symptom, the underlying problem is the real issue here and councils alone cannot solve this problem," he told Radio New Zealand.

Mr Pullen said police were expecting the boyracers to spread out.

They would be reviewing the weekend's operation to make sure they were prepared for everything next year.

As a result of the weekend behaviour there had been major disruption to traffic flow.

A section of Harper Avenue was closed for nearly two hours while police officers restored order and the mess was cleared away by contractors.

While no arrests were made at the time, police have identified some of the offenders and those people can expect to be charged, Mr Pullen said.

There had been 20 cars ordered off the road, 10 drivers processed for drink driving, and over 400 infringements issued for a range of driving offences including speeding and noise offences.

While police were kept busy there were no serious incidents.