Fare evasion or fare dodging, rarely called ticket evasion, is the act of travelling on public transport in disregard of the law and/or regulation by having deliberately not purchased a required ticket to travel (having had the chance to do so). It is a problem in many parts of the world, and revenue protection officers operate on many systems. Often ticket barriers, manned or automatic, are in place at stations etc. to ensure only those with valid tickets may access the transport. The term fare avoidance is sometimes used as a synonym and sometimes used to refer to the lawful use of much cheaper tickets.
Fare evasion and fare fraud is a crime in most jurisdictions. The fare not paid, compared to potential penalties and hassle, is generally considered "not worth it".
In the transit world, fare abuse studies are sometimes shrouded in utmost secrecy and treated like classified information, but it is widely discussed in popular press, local television news, criminal justice literature, economics research, and internet blogs; in New York, New Jersey, Boston, Chicago, Atlanta, San Francisco, Los Angeles, Seattle, Vancouver, Edmonton, London, and Paris. Four agencies (TransLink, King County Metro, Edmonton, New York) made evasion audit findings public, San Francisco (Muni) and Atlanta (MARTA) presented papers, while Toronto addressed evasion in a fare collection study, at least one confidential international benchmarking study was published, and Federal Transit Administration has even requested special studies of non-farebox passengers within the context of National Transit Database ridership reporting.