The Franco-Belgian engineering firm Société Franco-Belge built the CQ310 rail cars for the Metropolitan Atlanta Rapid Transit Authority. The cars were built between 1976 and 1980 and entered service between 1979 and 1981.
Two of the cars — 101 and 102 — were unpaired, while 111 and 112 were converted to a work unit. Two others — 103 and 104 — were scrapped following a 2019 derailment.
Cars 501–520 were all single units and retired in 2006. After their retirement, MARTA stored the cars at Avondale Yard until 2023, when it sought to dispose of them in preparation for delivery of CQ400 pilot cars.
MARTA donated car 509 to the Southeastern Railway Museum in Duluth, Georgia, and car 510 to the Trolley Museum of New York in Kingston, New York.
The cars featured Adtranz/Bombardier MITRAC 1508C traction motors.
