Have completely unrestricted and unsupervised phone access (so not even having to leave phone downstairs at nighttime)
Work part-time if still at school or college.
Learn to drive (either self-funded from wages or with parental help)
Travel in a car driven by a 17-year-old
Stay overnight at the home of a friend you do not know
Use public transport alone at night
Regulate their own sleep, even if this means getting out of bed at 3pm on a weekend
Stay home alone overnight or for multiple days
Be out and about without you know really knowing exactly where they are at any given moment