Sikgma, at the Summernats. Click for more photos

Summernats 26, 2013.

Sikgma, at the Summernats. Photo: Jay Cronan

Police are investigating two assaults at Summernats, arrested two people and issued three summons for traffic offences, but said the car festival was a well-run event.

Earlier, co-owner Andy Lopez said the 2013 Summernats was the most successful in the event's recent history, with a 15 per cent jump in crowd attendances and vehicle entries.

''Initially, we had thought last year's 25th anniversary event, which attracted 90,000 people and 1500 entrants, would be hard to beat,'' he said. ''By November, we knew we were on track to exceed both figures and we have finished up with 101,486 visitors and 1767 entrants.''

While the family-friendly formula Mr Lopez and his colleagues have been pushing since they took over the event four years ago has contributed to the growth in numbers, other factors have played an important role in turning Summernats support around. ''We have added new attractions, new reasons to come, to the mix,'' he said. ''We had 10,000 people rocking along to the [hip hop group] Hilltop Hoods on Friday night and 15,000 watched the qualifying rounds for the Burnout Masters.''

Mr Lopez said Summernats had been arrest-free for the second year in a row, a statistic he could not help comparing with the more than 30 arrests at the Boxing Day Test at the MCG. However, that may change as late on Sunday ACT Policing was investigating allegations by a young man and woman they had been assaulted inside the precinct about 10pm on Saturday.

Police are seeking witnesses to the assaults, which were separate incidents although both happened about 10pm on the southern side of the EPIC precinct.  They ask anyone who saw the assaults to contact Crime Stoppers on 1800 333 000 or  at www.act.crimestoppers.com.au.

"While there were no arrests within EPIC, police are investigating the assault of a 28-year-old woman and a 22-year-old man on Saturday, January 5. The woman was struck from behind at the side of her head, she fell to the ground and was conveyed to The Canberra Hospital for treatment," police said.

There were two arrests and three summons issued for traffic offences, and 50 vehicles were issued with defect notices over the four days. One vehicle was seized and impounded after a member of the public reported the driver for doing a burnout in Lyneham.

Overall, police issued 81 Traffic Infringement Notices and made 19 cautions during the four days of the event - most of these issued in EPIC or surrounding suburbs.

"One of the highest recorded infringements was that of a motorcyclist with a learner’s licence. The rider, from Crace, was carrying a female pillion passenger and was recorded travelling at 120km/h in a 60km/h zone. He was issued with fines totalling $1916, and incurred the loss of six demerit points," police said in a statement.

Officers conducted 418 random breath tests, and one person - with a blood alcohol reading of 0.122 - was caught. This driver was issued an immediate suspension notice.

Police helped event security staff evict 24 people from the EPIC precinct.

The operational commander, Acting Superintendent Rod Anderson, said earlier that police were generally pleased with the crowd behaviour.

''As expected, it has been a busy time for police,'' he said. ''We have been active in our support of the event security staff, and our officers have been very effective in maintaining a visible police presence not just around Exhibition Park and the surrounding suburbs, but in other identified hot spots such as Lonsdale Street in Braddon.''

Police supported event security staff when evictions where necessary, while around-the-clock patrols monitored issues such as drink-driving, public road burnouts, antisocial behaviour and speeding.

Heatwave conditions on Saturday and Sunday brought special challenges, with 32 people treated for heat stress by ambulance officers and paramedics on the Saturday.

Mr Lopez said the Summernats team had prepared for the heat, with spray stations set up around Exhibition Park. Also, free water was provided. On Saturday, when people were lining up for extended periods to come through the gate, team members had handed out bottled water, he said.

The 2013 Grand Champion Award, which went to Mick Fabar for his 1967 XR Falcon sedan, offered an interesting insight into how petrol-heads might cope in a post peak-oil environment. Mr Fabar's vehicle is claimed to be the world's first eco-friendly Super Elite muscle car, a 447-kilowatt turbocharged biodiesel V8 rated as having a carbon footprint of zero, according to Bond University experts.

As the Summernats crowds began making their way back to homes in all parts of Australia late on Sunday, police warned they were maintaining a ''high visibility'' patrol presence. They said any fans tempted to emulate the antics of their burnout heroes on the public roads would do so at their peril.

with staff reporters