A whole area of collecting. You can usually find tokens LIKE this in the 6 for a dollar bin at coin shows. However, just like casino chips, some are harder to find (scarce) and worth more.

My Brother is a railfan and collects these.

"About 12,000 different transportation tokens have been catalogued, and it is one of the most popular token collecting catagories." Alpert and Elman 1992 "Tokens and Medals"

They also reference a price guide, but give the following general value guide. Streetcars, railways, trains... Pre-1900 $1-$3, 1900-1950 15-30c, 1950-present 15-30c.

Atwood-Coffee Catalogue of US and CAN transportation tokens, 1983. Vol 2 Coffee 1984.

It's called Vecture - passage/travel money.