What's an Avatar?
"Avatar's make a transport system… who it is. Start losing Avatars, and it's like having bits of your brain chopped out one at a time." - John, the Airship Stowaway
Avatars are what make a transport system more than just a collection of routes between places. They are the people who give it a personality, and the vital spark of life.
How many Avatars are there?
"… from the mother with a pushchair, to the fit young man who won't get out of the seat to help an old lady. Good or bad, they're all here." - Monty, First Class Passenger
No one is really sure. Think of all the different types of people that you meet on a train, whether it is the passengers or the crew. There is one Avatar for every type of person that you meet.
How does someone become an Avatar?
" I go to work on the fifty-two each morning, and come back on the eleven minutes past." - the Commuter.
If someone is the best example of their type, they will end up as an Avatar. The Railway will suck them into itself, and they will become an Avatar.