I can't tell you how many times I've had a child fall asleep while on the back end of a trail-a-bike, tandem or or while riding on the bike rack (pillion style)! I think we've logged at least 100 miles doing this--yet we never lost a child. They have seemingly miraculous balance while sleeping...
(I know that technically this might not fit the thread.)
yes, at a stop light, after a marauders ride. and dozed off while riding for a brief second