Infamous pub crawl - the 'RoUndie 500' - behaving so far

The RoUndie 500 pub crawl, organised by the University of Canterbury's Engineering Society (Ensoc), is the successor to the Undie 500. Photo / Supplied

An infamous university student pub crawl has been well-behaved so far today, but wary police are aware "the day is but young".

The RoUndie 500 pub crawl, organised by the University of Canterbury's Engineering Society (Ensoc), is the successor to the Undie 500, scrapped in 2009 after drunken riots and arrests.

Last year's event was also criticised for bad taste themes and costumes, some of which being deemed sexist, racist or poking fun of ebola and Malaysia Airlines.

But today, the pub crawl around rural Canterbury has been kept under control.

Students have dressed up and decorated their cars. Scooby Doo's Mystery Machine has been spotted, along with a Donald Trump US presidential campaign car, the A-Team's van, and Thomas the Tank Engine.

This year, RoUndie entries were assessed both well before and on the day of the event.

Participants were required to submit car themes and participant costume proposals at least three weeks beforehand, with entries moderated by a screening committee of representatives from Ensoc, the University of Canterbury Students' Association (UCSA) and the university. Inappropriate entries will be advised in time for any issues to be addressed.

Police officers also checked each vehicle for safety and a sober driver.

But some cars are starting to fade under the rigours of the day.

Canterbury Police's district command centre has received reports around the Dunsandel area this afternoon of "stuff falling off cars".

"A lot of guys and girls have put a lot of work into their cars, but obviously haven't done any wind tunnel testing and bits and pieces have fallen off as they travel," a police spokesman said.

He reminded students to ensure their cars are roadworthy and not creating any dangers for other road users.

No bad behaviour or drunken antics had been reported to police by mid-afternoon today.

"That may change as the night goes on," the police spokesman said.

"The day is but young."