Mr Pain asked the students how many drink-drivers they thought were recorded in Hawkes Bay in 2012.
"There were 1391. Most people think there might be about 500 but it's almost triple that. Over the last five years, 1700 have been under the age of 20, that's about 300 a year, which is your age group," Mr Pain said.
"We want to change your attitude. Most of you will be getting to the age where you're going out and socialising and there's going to be a lot of pressure on you."
He said the expo was not "anti-drinking" and emergency services were not aiming to be "the party police".
"But we want you to think about the end of the night when you're going to head home. The crashes I have attended often involve instances when drink-driving was not intended. But most people go out and something happens which changes that."
Mr Pain asked the students to respect the "real-life stories" other expo presenters passed on to them. Some of the presentations featured photos of crash injuries, video clips of ambulance and hospital staff retelling their experiences at crashes, as well as an animated video reconstructing a fatal crash. All related to Bay crashes.
DHB public-health nurses highlighted the Yeah-Nah campaign on easing up on alcohol. Students were reminded not to use a cellphone while driving, and Mothers Against Impaired Driving, Directions Youth Health Services, blood-donor recruitment and Students Against Drink Driving also had advice for them.