My kids used to come home on the bike and just throw it down on the driveway. I would ask them to bring up to the house, and most often would check.
I was running late one morning, neglected to check, and ran over one of the bikes which then poked a perfectly round hole into the gas tank of my (then) '73 Impala. I can't exactly recall the amount of gas that thing held but it was most likely a small environmental disaster on the drive there. The extra bonus being I was REALLY late then...