after the model year, the Columbia and Century Class were also discontinued (in North America). In line with the Argosy, production of the Century Class shifted entirely to export. The Coronado long-hood conventional was joined by the Coronado SD (developed primarily for vocational applications). In 2010, Freightliner introduced its first diesel-electric hybrid vehicle, based on a M2 106. For 2011, the company debuted the SD model family. Alongside the Coronado SD introduced the previous year, two new models were added, the 108SD and 114SD, derived from the M2 model family. In 2012, Freightliner celebrated its 70th anniversary, unveiling the Revolution concept vehicle. Constructed of carbon fiber and plastic, the cab featured a redesigned layout. Intended for use by a single driver, the passenger seat was replaced by a jumpseat (converting into a sleeper bed); to optimize trailer hookups, the design included a rear access door. As a result of increased demand for the Cascadia, parent company DTNA announced plans in 2012 to expand its workforce at its Cleveland, NC facility. Alongside the Cascadia, nearly 20% of trucks produced by the plant (including the Argosy and Century Class) were exported to South Africa, Australia and New Zealand. In 2013, Freightliner expanded its alternative-fuel lineup, adding a natural-gas version of the Cascadia. Introduced as a premium option for the Cascadia, the Cascadia Evolution further enhanced aerodynamics and fuel economy (distinguished by its full rear wheel covers) and improved interior features. The Coronado was added to SD model family, renamed the 122SD. On August 22, 2014, the Cleveland plant built the 3 millionth vehicle of Daimler Truck North America, a 2015 Cascadia Evolution. At the time, Freightliner employed 2600 workers at the facility and 8000 employees in North Carolina. In May 2015, the Freightliner Inspiration was unveiled near Hoover Dam. The first road-licensed autonomous semitruck, the Inspiration was loosely based on a Cascadia. A Level 3 autonomous vehicle, the autonomous driving system was equated to the autopilot system of an airliner or a Tesla (requiring operator presence). For 2017 production, Freightliner introduced a second-generation Cascadia, adopting elements of the design from the Inspiration autonomous vehicle. For 2018, Freightliner debuted the EconicSD low-entry COE. Intended largely for refuse applications, the model line is an adaptation of the Mercedes-Benz Econic. In September 2019, parent company Daimler announced that it would be halting "its internal combustion engine development initiatives as part of its efforts to embrace