The RegioSprinter is a German diesel railcar built by Siemens-Duewag for rapid regional railway services. Originally the RegioSprinter was designated as a Regional Combustion-engined Railbus (Regional-Verbrennungstriebwagen or RVT) by Duewag AG.Developed as prototypes for fast regional railway services on the plains, the RegioSprinter still has the fastest acceleration of any multiple unit or railbus in Germany. Due to several technical and conceptual defect, however, only very few were built.