AutoTram® Extra Grand

The Longest Bus in the World

The AutoTram® Extra Grand – currently the longest and one of the most innovative busses in the world – combines the advantages of conventional trams with those of buses. It has a passenger capacity of over 250, can be driven fully electrically over a longer distance, is flexibly operable on diverse routes, and, perhaps most importantly, the costs for acquisition and operating are only half as high as those of trams.

One feature of special importance is the excellent maneuverability of the double-articulated, over 30 m-long vehicle. Due to its novel joint and gangway systems in combination with an electronic multi-axle steering system, it is almost swept path-free in curves, both in forward and in reverse drive. With its turning circle of 12.5 meters, which is extremely small considering its length, the AutoTram® Extra Grand meets the registration criteria for road vehicles in public transport. Due to its high passenger capacity, comparably low costs and high operational flexibility, the AutoTram® Extra Grand is especially well-suited for urban areas and mega cities with a fast-growing demand for transportation.

The foundations for the intermediary vehicle concept have been developed at the Fraunhofer IVI over the course of several years.

Vehicle Technology


Development and simulation of conventional, hybrid and electric drivetrains; intermediary vehicles; hybrid, battery und fuel cell buses; energy management and auxiliary control strategies; operational strategies


Energy Storage Development

Modeling, configuration and state diagnosis of electromechanical, electrochemical and thermo-dynamic storages and converters; complex development environment for the design and modeling of the propulsion control for vehicles and transport systems; control and regulation of mechatronic systems

Multi-Axle Steering System and Lane Guidance

Novel multi-axle steering systems; cornering characteristics and vehicle dynamics (kinetic and kinematic multi-body systems, simulation); automated lane guidance for vehicles; test vehicles with measuring equipment;  

Services and Tools

System solutions for the fast transmission of electric energy to vehicles; ageing diagnoses and operating concepts

Machine-based methods for the planning and assessment of obstacle bypassing; consumption displays; feasibility studies; risk analyses

Models of transport demand and transport network for public and private transport; Studies on the implementation of innovative transportation systems; operating concepts for public transport systems; lifecycle cost and cost-benefit analyses