Originally Posted by fastair

No, there is no scanner at the gate to state when a person deplanes, just when it blocks in. De planing can take a person 30 seconds or 20 min depending on aircraft type and seat assignment. They also don't know how mobile or motivated a person is. If they are running or if they gave up and are in line to get rebooked. House arrest bracelets would, in fact, make your statement plausible, but many people would not submit to the cost of such a device nor the invasion into their privacy. I mean, the technology exists to gps/cell track the movement of people, but as individuals, predicting actual specific behaviors is not currently, a realistic and accurate science. Yes, generically, flights are held for connections, but it's a hit or miss proposition, some times it makes situations better for travelers as a whole, sometimes it makes it worse.