Twenty-one students "in different levels of intoxification" were found by Otago police crammed into an enclosed furniture removal trailer heading to a day at the races.
The students were found in the trailer at a service station in Mosgiel, 15km southeast of Dunedin, while on their way to Wingatui races in the town on Tuesday.
Police said they got a tipoff from a member of the public.
Constable Jacqui Ballam told the Otago Daily Times while the students were right to appoint a sober driver, cramming into a trailer was not the appropriate option.
The students were told to walk the rest of the way while the driver was issued with a traffic infringement notice and faced a fine of up to $1000.