@ Margery

I too get irritated at people who take unfair advantage of the "free gate check" loophole that you describe. Not only do they block the narrow aisles and cause possible injuries, but it is also not fair to others in the plane who actually PAY for their checked bags.

However, don't you think the airlines would've eliminated this loophole already if they had found it practicable and/or economically beneficial? Here's why I think the airlines don't do it: checking in over-sized carry-ons at the gate would cost the airlines a lot in terms of additional staff for the purpose (processing payment etc.) and subsequent delay in take-off. Airlines operate their planes at very tight turn-arounds (usually 30-40 minutes), and it would actually cost the carriers more to have to formally check the bags than to just toss the few odd bags into the baggage hold and get the plane going on time.

I do not agree that the TSA should be made responsible for the baggage check-ins. Enforcing baggage restrictions is not within their mandate, and the TSA has already encroached a lot in our lives.

The best solution is for the airlines to screen carry-on at the check in counters for size/number limitations. Let the passengers carry only the allowed carry-on beyond the check-in desks.