Restriction placed on driving or drinking, say (3,5)
I believe the answer is:
age limit
(Other definitions for age limit that I've seen before include "I am legit (anag)" , "It can mean one is too young or too old" , "Regulation regarding length of time one has lived" , "Regulation based on year of birth that sets down when one can no longer do something" , "Maturity restriction" .)