The GMC RTS order was the largest in the agency's history. Two hundred and sixty ADB (Advance Design Buses) were delivered in 1980 and early 1981 numbered 1000-1259. They were the first buses delivered with power steering. They had fiberglass side panels and doors mounted on stainless steel frames. They also featured cushioned seats, deep tinted windows, PA system, high back driver's seat, tilt steering, and were powered by the new Detroit Diesel 6V92 engine mated to the Allison V730 three-speed transmission. In 1989, forty buses (1220-1259) were leased to Greyhound Lines Inc. for the federally funded Private Enterprise Participation (PEP) project that the then Republican administration forced on the agency. MDTA and Greyhound competed on five parallel routes to see who could do it cheaper. A little over a year into the three-year project GLI abruptly pulled out. MDTA took the buses back, and they were trashed. All were deemed unfit for service. MDTA scrapped quite a few of them, the others were refurbished and put back into service. In 1991, MDTA leased eight RTSes to Mayflower and were re-numbered 1-8 in another privatization attempt. Those buses were scrapped at the end of lease. In 1992, MDTA started refurbishing the RTS fleet.  The coaches received new floors, air ride driver's seat, Vultron electronic destination signs, and hard plastic seats. They were retired in 1999, when the 9800/9900 series NABI low floor coaches replaced them. Bus 1207 was the last RTS to run. Some of the RTS buses were converted into mobile command units and are still in use today. Community Coach of West Palm Beach bought and re-sold quite a few of them. Some went over to Disney Transport and are still in use today. MDT still has two RTS buses on the property.
Bus 1206 at Mt. Sinai Hospital in Miami Beach and the 1000 parked behind a supervisor vehicle.
Bus 1003 as a Miami-Dade Police Command unit and bus 1253 at CBD Terminal in downtown Miami.
Bus 1052 in downtown Miami and bus 1199 at Central yard.
Bus 1254 on the W in Miami Beach and bus 1259 as a MDPD mobile command unit.
Bus 1097 at the Community Coach yard in West Palm Beach, This bus was sold and converted into a mobile home.
Some of the re-numbered RTS buses that were leased to Mayflower sitting at a yard in Medley.