The "flagship" of the Setra TopClass 400 can be seen in the open-air section this year. Measuring 13.89 metres in length and with a height of four metres, the double-deck S 431 DT represents the top of the Setra touring coach range.

Various aspects of active and passive safety have been redesigned and improved. New features include the transverse-braced bodyshell with its frame members which result in higher torsional stiffness and thus give the vehicle better directional stability. The 2550-mm width of the vehicle is an additional factor which ensures stable handling. The Electronic Stability Program (ESP), Lane Assistant (SPA) and Active Brake Assist (ABA) also contribute to the overall safety of the vehicle and passengers.

The vehicle on show in Belgium can accommodate 78 passengers in comfortable "Nimbus" individual reclining seats. A galley with a 40-cup coffee maker is inte­grated in the lower deck. The Coach 2000 Professional radio system delivers a very pleasant listening experience and features individually adjustable loud­speakers above the seats.

The S 416 HDH which Setra is showing at Busworld 2009 is the latest member of the TopClass 400 family of touring coaches. Designed as an economical variant offering optimum seating capacity, this model has been available since autumn 2003. The S 416 HDH comes with every conceivable comfort feature as well as a large luggage capacity to provide an outstanding touring experience. The glass-roofed three-axle model on show in Belgium has a leather steering wheel with an aluminium insert, 34 "Ambiente" individual reclining seats and a new six-part lounge section with "club table" lighting. Additional comfort features include a galley with a Jura coffee maker and a hot-dog heater, electrically folding 19-inch flat-screen monitors and a multifunction aerial for the radio, telephone and navigation systems.

The show vehicle is also equipped with the latest safety systems, including the Electronic Stability Program (ESP), Lane Assistant (SPA) and adaptive cruise control (ART) with Active Brake Assist (ABA). Furthermore, the vehicle is equipped with an electronic level control system (ENR).

Setra introduced a new dimension in touring coach design with the launch of the TopClass 400 in 2001, ensuring a consummate touring experience for passengers and driver. This is thanks to innovative comfort features such as back-friendly seats, multimedia systems, a range of kitchen appliances and the unique glass roof above the centre aisle. The ergonomically designed cockpit is a blend of elegant practicality and aesthetics.

European journalists from the motoring press had a host of good reasons to vote the TopClass 400 “Coach of the Year 2002” just eight months after its debut. The panel of judges cited its impressive technology and a remarkable design that struck a perfect balance between form and function as just two of the reasons for their decision. Since then, the TopClass 400 has picked up many more inter­na­tional accolades and awards. A case in point was the "Commercial Vehicles of the Year 2007" readers' poll, in which a total of 8500 participants voted the Setra TopClass 400 the winner in the "High-deck touring coach" category for the third time.

The TopClass 400 is also state-of-the-art when it comes to safety. All the vehicles are fitted as standard with disc brakes, the Electronic Braking System (EBS), anti-lock braking system (ABS), acceleration skid control (ASR), Brake Assist (BA), and Electronic Stability Program (ESP), an active system designed to enhance driving safety and handling stability. Since 2005, Setra touring coaches have also been available with adaptive cruise control (ART) on request. This system reduces the driver's workload on motorways and other major roads. When the proximity control system detects a slower-moving vehicle ahead, it automatically brakes the coach until a distance preset by the driver is reached. This gap is then constantly maintained by the proximity control system. Since 2005, Setra has also offered the Continuous Braking Limiter (DBL) as standard. The system automatically brakes the coach, for example if it exceeds the legally prescribed speed limit of 100 km/h by accelerating under gravity on a downhill gradient. Setra also offers Lane Assistant (SPA) as an option. This system uses a video camera to monitor the distance between the vehicle and the lane markings and detect any tendency by the vehicle to depart from its lane. If the vehicle appears likely to cross this line, the driver is immediately warned by a pulsating mechanism in the seat – which goes unnoticed by the passengers. As the warning is triggered when the vehicle reaches the outside edge of the lane marking, the driver is given the greatest possible scope for taking remedial action. Lane Assistant is activated automatically at speeds above 70 km/h.

At the end of last year, Setra delivered the first S 416 HDH equipped with Active Brake Assist (ABA). This system reacts to slower moving vehicles in front by providing an escalating series of warnings and initiating emergency braking if there is a risk of a collision. It operates in combination with the adaptive cruise control (ART) function, whose sensors are used to detect moving "obstacles" ahead of the vehicle. The system therefore actively helps to prevent head-to-tail collisions, meaning that it can save lives.

The TopClass 400 generation comprises the 10.16-metre-long S 411 HD club coach, the 12.2-metre S 415 HD, the 12.3-metre S 415 HDH with three axles, the 13.19-metre three-axle S 416 HDH and the 14.05-metre S 417 HDH. The flagship of this Setra premium range is the 13.89-metre S 431 DT double-decker coach. Setra introduced the S 417 – which was specifically designed to meet North American standards (in terms of vehicle dimensions, emissions standards and customer requirements, for example) – in the US market in the spring of 2003.