But police say they expect another well-behaved event, on par with last year's controversy-free festival.

The four-day car festival revved up on Thursday, with a high-profile police presence planned for the Exhibition Park precinct, Northbourne Avenue, and Lonsdale Street.

The operation will include the closure of Northbourne Avenue on Friday for the annual City Cruise, which has become a quasi-opening ceremony for the iconic event.

A number of alcohol free areas will be enforced during the parade to ensure families could watch without fear of anti-social behaviour.

ACT Policing said the focus throughout the weekend would again be on random roadside drug and alcohol tests, and irresponsible and dangerous driving behaviour.

ACT law means police have the power to seize vehicles for offences such as burnouts, menacing driving or street racing on public roadways.

Last year, three vehicles were impounded and 67 traffic infringement notices were issued.

But only one driver returned a positive reading after police conducted hundreds of random breath tests.

ACT Policing station Sergeant Donna Hofmeier, who is operational commander for the event, said she hoped last year's good behaviour continued at the 2015 festival.

"We were pleased with crowd behaviour at the 2014 Summernats street machine festival, with minimal police involvement regarding anti-social behaviour," Sergeant Hofmeier said.

"We hope to see the same, if not better, results this year.

"A lot of hard work goes on behind the scenes to stage this event and the organisers were praised for the smooth running of Summernats 27."

Sergeant Hofmeier said that, in line with previous years, police would have a minimal presence inside Summernats.

"Our main focus is outside the venue, making sure the traffic is running well, ensuring there's no anti-social behaviour.

"But, obviously, there's the expectation that there'll be the same level of public safety inside and outside, so we'll have a presence inside."

ACT Policing worked closely with the event's organisers to ensure a safe environment for all, Sergeant Hofmeier said.

"Obviously, we want people to come and enjoy themselves in a happy and safe environment, but we won't tolerate criminal and anti-social behaviour.

"Police will also be supporting event security staff when evictions are necessary."