Three drunk drivers were arrested leaving Toast Martinborough on Sunday - including one who was more than three times the limit.
Masterton police Senior Sergeant Carolyn Watson said police stopped 398 people at a Ponatahi Rd checkpoint as they left the food and wine festival.
"Although the readings are high, which is disappointing, for that number of people being stopped and only three people found means the message is getting through to the majority."
A Masterton man in his 40s was caught with a breath alcohol limit of 1405mcg at the checkpoint. The limit is 400mcg per litre of breath. Ms Watson said he was "pretty hammered".
A Masterton woman, 24, blew 850mcg and a 20-year-old Martinborough man, who was stopped by a patrol car elsewhere in the township, blew 857mcg.
The checkpoint had to be prematurely closed and traffic diverted through Ponatahi Rd after a 31-year-old Belmont woman was hit by a bus on Kitchener St and the road closure was causing delays.
The majority of the 10,000-strong crowd were well behaved, said Ms Watson, although there were eight arrests.
"More people were arrested because more police were there and we decided to stamp out early, and the tolerance level was lower. We did send a bit of a message."
Most festivalgoers had gone home by about 9.30pm.
Toast Martinborough's decision to swap leftover festival francs for vouchers rather than bottles of wine meant fewer people were drinking in the Square after wineries stopped selling alcohol at 6pm.