There were a number of different configurations in each of the series and the model numbers designated the following equipment:


First designed as an interim bus while the transit community waited for the Transbus, the RTS achieved permanent status when the Transbus project was cancelled in 1979. The first RTS deliveries were 15 to Long Beach (California) Transit in October, 1977.

Although display name plates inside the buses show the name as RTS-II, the actual progression of models has been identified by a Series number. The Series 01, ordered by a consortium of transit agencies in California, Texas and Massachusetts, was delivered during 1977 and 1978 and did not fully meet the Department of Transportation specifications for an Advanced Design Bus (ADB).

The most obvious external identifying feature of the Series 01 is the front bumper which is different from all later models. Some 01 buses have been retrofitted with the new, simpler bumper. The sloping rear could be either a Series 01 or 03, but this feature is often eliminated by retrofit of improved air conditioning. Of several vendors which supplied air conditioning upgrade packages, the Thermo King looks very much like the factory-installed version.

Beginning in April, 1978, the Series 03 (there was no Series 02) was a fully qualified ADB. Both the 01 and the 03 had a small louvered panel at the rear of the side windows.

In August 1980, the series 04 RTS was introduced with the air conditioning condenser relocated above the engine, causing the pronounced slope on the rear profile to be replaced by a square-back appearance. The reduction in air conditioner maintenance was so dramatic that many of the original slope-back RTSs have been retrofitted. First production models of the square-back design went to VIA San Antonio (123) and Miami, Florida (260). The 04 introduced a new style rear bumper.

The Series 06, introduced in 1986, included many technical changes including improved window latches and seals and a beam front axle in place of the independent front suspension.

The most obvious 06 appearance change is often hidden by large advertising panels along the sides. The exterior fiberglass panel above the rub rail between the front wheel and the exit door or between the front wheel and the rear wheel became one piece without joints. Also, the rub rails on the 06 have exposed attaching holes that are not present on previous series.

The RTS model numbering began with TH-8201 designating the first Long Beach buses. The "T" indicates "transit" and was intended to distinguish from parlor models which were being planned at that time but were never produced. The "H" indicates the 8V-71 engine and later models use a "W" for the 6V-71 engine. The "8" indicates the bus was assembled from eight five-foot modules, creating a 40-foot bus. A 35-foot bus has a "7" at that spot in the model number. The second numerical digit indicates the width; a "2" stands for 102 inches and a "6" stands for 96 inches. The last two digits indicate the series number. In the spring of 1979, the model numbers were slightly changed by transposing the second and third digits, thus the TH8603 became the T8H603.

The last RTS built by GM was completed in May 1987, ending 62 years of bus production at Pontiac, Michigan with the delivery of fleet #919 to Kansas City (KCATA). GM had delivered 11,932 RTSs, 7,136 with wheelchair lifts and 4,796 without lifts. The first order to be completed by Greyhound's Transportation Manufacturing Corporation was for New York, using bodies produced at Pontiac and shipped to Roswell, New Mexico.

Information from the Bus World Encyclopedia of Buses - 1988