I remember once speaking to a DART Light Rail fare enforcement officer and mentioning that in Boston we still collect fares at the front door. She was speechless. Other rich Western countries would similarly laugh at us if they understood that still happens on almost every bus line in America. Requiring people to line up at the front door, delaying all passengers and paying an expensive professionally trained operator to waste up to 30 percent of running time collecting fares, at a time when we're cutting crowded service for lack of money, is beyond ridiculous.
A proof-of-payment fare collection system (TCRP Report 96) drastically reduces travel times and lets us use the savings to spend our resources where they are needed: more service.