We all tell our kids that if they're at a party and their friends have been drinking, don't ride with them.
Here's a great suggestion, put the UBER app on their phone. UBER is a car service that uses the GPS on your phone to schedule rides right away, 24 hours a day. If you open the app on their phone you can show them how to summon a car to pick them up. Tie the app to your credit card and your daughter or son won't need cash to get home.
So many kids don't want to call mom or dad and admit they were partying too hard or that their friends are in trouble. But we want them to get home and be safe. This is a great way to be sure they get home.
My son's car after a drunk driver hit him in 2010. He was not drinking. He is fine, but if the other driver had used UBER or taken another ride he would not have endangered my son.
Here's their website. There are apps for Android and iPhone.