The world's longest bus, the new AutoTram Extra Grand, was presented to the public for the first time in the historic city center of Dresden, Germany on August 22.

The multi-unit vehicle with rubber tires is more than 98 feet long and has a capacity of 256 passengers. It has been developed and constructed within the »Innovative Regionale Wachstumskerne« research program, which was initiated by the German Federal Ministry of Education and Research (BMBF).

The AutoTram technology is based on a vehicle concept developed by the Fraunhofer IVI, combining the advantages of rail and road-bound transport systems. So far, the concept had only been used for research purposes, but is now applied in practice.

Due to its high transport capacity, the AutoTram Extra Grand bridges the gap between conventional city buses and trams, offering new possibilities for an environmental friendly public transport. The vehicle is suitable for the use in BRT (bus rapid transit) systems, according to company officials.

Another significant technical feature, apart from the vehicle’s dimensions, is the train-like guidance of the vehicle. The AutoTram Extra Grand has four guided axles, three of which can be controlled by means of a secure electro-hydraulic actuator system. With the multi-axle steering system, the vehicle can be maneuvered like a 12-meter bus both forward and reverse.

Fraunhofer IVI developed the control algorithms and the battery storage system, enabling all-electric operation for a distance of 8 kilometers. With the compact range extender, batteries can be recharged on route. By means of a predictive energy management, energy-efficient operation is guaranteed.

The innovative public transport vehicle has been developed in joint research with the Institute of Electrical Power Engineering, TU Dresden, and Wittur Electric Drive GmbH, who were in charge of developing the high efficient drive engines, as well as the Dresden-based M&P motion, control and power electronics GmbH, who contributed power electronics, the vehicle computer and supercapacitors.

The Dresdner Verkehrsbetriebe AG were responsible for consulting in transportation and traffic sciences. The type approval was carried out by the DEKRA and the AutoTram Extra Grand was constructed by bus manufacturer Göppel Bus GmbH in Thüringen.