This is slightly lower than the number of riders recorded in 2018 and represents the system's third consecutive year of fallen ridership. MAX ridership peaked in 2012, when the system recorded around 42.2million annual passengers. 2016 marks the last year ridership increased; this was due to the opening of the Orange Line. TriMet attributes falling ridership to perceived crime within trains and stations and lower-income riders being forced out of the inner city by rising housing prices. , MAX is the fourth-busiest light rail system in the United States after the light rail services of Metro Rail in Los Angeles, the MBTA in Boston, and Muni Metro in San Francisco. As is standard practice on North American light rail systems, MAX uses a proof-of-payment fare collection system and its stations do not have ticket barriers. Most ticket vending machines at stations accept cash as well as credit and debit cards but some machines accept only cards. TriMet employs an automated fare collection system through a stored-value, contactless smart card called Hop Fastpass, which can be purchased from participating retail stores. Alternatively, chip-embedded, single-use tickets may be purchased from ticket vending machines. A virtual card is available to Android and Apple users. Smartphones with a debit or credit card loaded into Google Pay, Samsung Pay, or Apple Pay can also be used on the MAX network. Portland Streetcar ticket vending machines issue two-and-a-half-hour tickets and one-day passes that are valid on MAX. Before boarding a MAX train, riders must tap their fare medium onto one of the card readers that are located within the station. Fares are flat rate and are capped according to use. Using Hop Fastpass, riders may transfer to other TriMet services, C-Tran, and the Portland Streetcar. From the MAX system's opening until 2012, riding trains within Fareless Square, which was known as the Free Rail Zone from 2010 to 2012, was free of charge. Fareless Square included all of downtown and, starting in 2001, part of the Lloyd District. The 37-year-old fare-free zone was discontinued on September 1, 2012, as part of system-wide cost-cutting measures. As part of the same budget cuts, TriMet discontinued its zonal fares and moved to a flat-fare system. Zones had been in place since 1986; higher fares were charged for longer journeys across four paid zones. The MAX Mall Shuttle operated on weekday afternoons from when it was introduced on September 14, 2009, until 2011.