Rheinbahn Düsseldorf for Bus Simulator 21 is a free utility add-on designed to enhance the gaming experience of bus simulation enthusiasts. This program features a detailed representation of the Rheinbahn bus network, supporting a variety of bus models including the MAN New Lion's City G, MAN Lion's City A23, and Mercedes-Benz Citaro G among others. Players can immerse themselves in realistic bus operations while exploring the defined routes and schedules of Düsseldorf's public transport system.

The add-on also includes an interior design that reflects the Rheinbahn aesthetic, allowing players to enjoy an authentic driving experience. Additionally, users are required to manually select the color gray within the game settings to achieve the desired visual effect. Overall, this program serves as a valuable resource for players looking to enhance their gameplay with realistic and immersive content.