"We're encouraging those involved to enjoy themselves within the bounds of the law.
"Those who go outside the law and are charged with an offence will be subject to a blanket no-diversion policy should they be prosecuted," Dunedin and Clutha area commander Inspector Dave Campbell said.
The no-diversion policy is one of the measures in place for this year's event, which begins with cars leaving Christchurch tomorrow morning.
A 24-hour liquor ban will be in place in North Dunedin from 6pm tomorrow until 6pm on Sunday and extra police staff will be on foot patrol in North Dunedin on Saturday.
Police have also arranged a secure parking area for Undie 500 vehicles.
Insp Campbell said officers were planning for the Undie 500, as they would for any similar event.
"We are hoping that students this year will have the common sense to have a good time without breaking the law.
"If the law is broken, then there will be consequences," he said.
• Dunedin Mayor Peter Chin last night renewed his attack on the Undie 500 event, labelling it a "drunken pub crawl" and saying he hoped it "snowed like hell" in Dunedin.
Speaking on TV3's Campbell Live programme, Mr Chin urged Engineering Society of Canterbury University president Carl Shrimpton - one of the event's organisers - to cancel the event, or stage it in Christchurch.
However, Mr Shrimpton, also appearing on the programme, said there was more to the Undie 500 than alcohol - pointing to the effort that went into preparing vehicles - and said "neither the DCC or myself has the power to stop people travelling to Dunedin".
"We are putting controls and measures in place we believe will control and mitigate the antisocial behaviour of the past," he said.
