I've always found this one of the more ridiculous products of being risk averse. On the Underground these calls come to BTP (we go from one to the next for a couple of hours every Friday and Saturday night when the trains stop), but we certainly don't go on blues and twos. We just go there, wake them up, ask them if they're OK and then walk them to the nearest bus stop. The only time I've ever fallen asleep on a night bus, the driver very kindly shook my arm until I woke up and sent me across the road to get the next bus back the other way. It's depressing to think that he was putting his job at risk to wake me up.