Security ... think about it!
I recently took my 90-year-old father to the airport so he could catch a flight to visit my brother in Chicago. He still walks on his own, but feebly. I had to leave him to not only maneuver through security by himself (taking off his shoes, etc.), but he had to negotiate the long concourse to his gate alone. He can do it, but it is physically and emotionally taxing, and he's too darn proud to ask for a cart, and all I can do is stand there helpless and watch him wearily shuffle away. My eyes tear, and I get angry at the insensitivity of our airport system.