"Fare Capping" is the term, in public transit or mass transit ticketing, of giving people a day pass or month pass when they have spent a certain amount of money on transit. Practically, fare capping can only be accomplished with a contactless card. It is easier to explain by example.

On Trimet, Portland's mass transit system, a 2 hour ticket is $2.50, while a day pass is $5.00. Before the introduction of fare capping, someone could theoretically spend $10 by getting tickets throughout the day. With fare capping, once they buy the second ticket, they automatically get a day pass. The same applies to monthly passes.

There are two benefits to fare capping. One is that it is a more equitable system. Lower income people, who may not have enough money to pay for a pass up front, could spend more money on fares than a higher income person who could pay for a pass at the beginning of each day or month. The second benefit of fare capping is that it takes away some of the doubt or confusion that might stop someone from using transit: I remember in the days before fare capping, wondering if it made sense to buy a day pass on a day I might take the bus more than once. Someone who is unsure how much transit they are going to use at the beginning of the month doesn't have to box themselves in with a decision. Often it is small worries like this that make people unsure about using transit.

The biggest drawback of fare capping is that it requires the deployment of IT infrastructure, and for customers to use cards. Somewhat unsurprisingly, one of the main sources for information about Fare Capping comes from a company that supplies IT to transit agencies:



https://www.initse.com/enus/news-resources/blog-podcast/fare-capping/