Revheads roll into Canberra for Summernats

The once-wild boys and girls of Summernats have grown up, and now their kids are the ones laying down rubber at the annual street car festival.

More than 300 pimped-out cars rolled into Canberra's CBD on Thursday to mark the official start of the four-day event, now in it's 29th year.

Thousands lined Northbourne Ave for what was the largest ever City Cruise, featuring - for the first time - highly-modified cars not normally allowed on the capital's streets under special permits.

"Our punters are safe, sensible individuals that like to have fun but there's no mucking up on the roads here," festival co-owner Andy Lopez told reporters.

"They get one crack a year to be at Summernats - nobody wants to get sent home early."

About 2000 cars are expected to participate in Summernats 29, with more than 100,000 people set to pour into Exhibition Park between Thursday and Sunday.

With no more wet T-shirt competitions or strip shows, Mr Lopez - who took over the once-infamous event in mid-2009 - said the festival was more family-friendly than ever.

"I think a lot of the wild boys and girls who were at Summernats in the early nineties have all grown up and become 40-year-old people who are probably a bit more sensible and like to get to bed a bit earlier," he said.

"They're also coming with their kids - we've got three generations of people that attend the Summernats together which is really special."

Unlike many other festivals around Australia, Mr Lopez said, Summernats was growing in popularity.

The event is locked in Canberra for at least another three years, with organisers already in discussions to extend that agreement.

"I don't know if I'll be here, but I think Summernats will still be here for Summernats 50," he said.