L.U.
I'm old school, no matter what. They have a shorter time under the wings of the parents, then on their as adults. Likewise, I told my children I am also held responsible for their actions until then, so I have to set rules. As they go on their own, they will be held responsible for their own actions and will have the rules of the laws to follow.
17yrs and until they graduated from High School. School night curfew is 10pm. Rest is important for the next day, both for the teen and the adult.
Weekends, (Good kid and priorities done) As long as I know his contacts. Who, What, Where, When and trust ... It's good to go. We have always made good efforts to invite his friends over to meet them (non-threatening/non-lecturing). When friends of your children get to know the parents, and there becomes a rapport. There also becomes a concience of us.
So, you work hard ... you can play hard ... within limits.