Due to traffic, I'd probably leave before 5 pm because that's when it starts getting crazy.
If it's after school, then I would do what I usually do before Jiu-Jitsu practice and go somewhere to study, eat, or take a walk nearby where I actually should be and get ready during that time too. That's because practice starts at 5:30 and I've tried to get out at 5 pm and ended up getting there 40 minutes late (usually, it's only a 15-minute drive from my house)
The roads are surprisingly more empty on a Saturday or Sunday so if it's on those days, I'd probably just head on over there at a decent time.