Ethics of waking someone up on the bus

Was on the bus to wem, sat next to a student who was folded over, (hopefully) asleep. I told myself the length of the busride that I'd wake him up once we get to the transit centre, so when the time came I shook him softly. He stayed folded over. Shook him again, again with kindness, and again he stayed put. I just got up and walked off after that, with guilt on my heart. Should I have been more forceful with my shakes, or should I assume the kid knew and assumed the risks of sleeping on the bus