Police in Exeter have credited Devon's youth service for a 50% drop in drinking amongst young people during the summer holidays.
Devon and Cornwall Police said they noted the estimated reduction in underage drinking in parks in the city.
The county council's Youth Service has a programme mobile youth club visits and street-based youth work.
The mobile units are designed to reach youngsters aged from 13 to 19 who would not normally visit a youth centre.
The council has three mobile units which have been used in Exeter, as well as in the east/mid Devon and north Devon areas.
They are fitted with seating for 10 people, a TV, a DVD player, music system and laptop computers.
Acting Chief Inspector Peter Coppin-Harris said: "There is an obvious link between crime and disorder, and underage drinking.
"We are extremely pleased that the mobile youth units have had such an impact, making our communities safer."
Devon County Council Principal Youth Officer Dillon Hughes said: "We knew we needed to get out to young people who would not normally walk into one of our youth centres or contact us.
"All the evidence suggested there was an issue there and we needed to create a flexible, inventive response."
The mobile youth units will be used in the Chulmleigh area next year.