Well, Bee, either of that or he'd have ridden straight out, shooting the checkout clerk on the way... You're wrong about 2) as well. If the trolley corrals have rough flooring (they don't necessarily in the UK, thought the entrance of them likely will), it's so that the store doesn't have to worry about slope i.e. it's primarily to stop carelessly parked trolleys following gravity & rolling wheresoever they will. Maybe not. It's certainly not what you suggested, anyway! ;-)