It's difficult for the old and infirm to get around today's big airports, especially with luggage. At the airport you can get a lift in an electric buggy, but it's rare because they require a human driver.
I suggest fleets of 1~4 seat automated buggies that follow preset paths to move people to
the gate efficiently. At the check-in the traveller swipes his/her boarding pass that tells the buggy the boarding time and route to the gate. There is an touch screen map of the airport with screen-buttons for going to the gate, stopping at the bathroom, duty free, lounge etc.
At each stop, the buggy checks you have taken all your belongings, reminds you how long you have before you need to hail another buggy and bids you farewell, freeing itself for a new user or returning to home base or a new location as instructed by the central control system.
For very long distances, buggies could drive onto special monorail trains or pull up at the station and allow the traveller to travel alone.