The Stadler Regio-Shuttle RS1 is the first widely used, new-generation, diesel railcar in Germany and Czech Republic for local railway services.

This construction was originally proposed to ABB (later ADtranz) by Design Triangle during a research study into weight reduction for high speed trains.

The study, reported in a paper to the Institution of Mechanical Engineers in 1996, showed that the diagonal pillar concept allowed mass reduction, improved passenger views and flexibility of seating layout, whilst maintaining adequate body strength and stiffness.

Its relatively small capacity (maximum under 170 passengers) is balanced by the fact that the vehicle can be driven in multiples of up to seven units.

A rake of five RS1's can thus handle a maximum of just under 850 passengers, albeit somewhat uneconomical compared with a locomotive-hauled train due to the fuel consumption of its ten diesel motors.

The following railway companies have Regio-Shuttle RS1's in their fleet: In 1999 the Deutsche Bahn began to place Class 650 railbuses into service and currently runs 74 units (as at: June 2005).

In 2011 České Dráhy classified new type of regional train as Class 840 (two magnetic track brakes for steep-grade service; gearing for 100 km/h)[5] for routes in Liberecký kraj and little different Class 841 (one magnetic track brake; maximum speed 120 km/h) for routes in Kraj Vysočina.

In December 2020 České Dráhy purchased an additional 22 units from SWEG Hohenzollerische Landesbahn, increasing the total number of Stadlers' diesel railcars from 33 to 55.