Daimler Buses: undoubtedly the number one for safety in Europe

BERLIN -- July 2, 2015: The undisputed number one among bus manufacturers in Europe is also the undisputed number one in safety technology – anybody wanting to lead the field in passenger transport must also deliver a first-class performance when it comes to safety. With Mercedes-Benz and Setra, Daimler Buses has both two leading brands as well as very different vehicles in the form of city buses and touring coaches under its aegis in terms of operating profile and technology. However, safety technology alone is of little use if operators do not order it and drivers do not use it responsibly. This triumvirate of manufacturer, operator and driver works well, as the accident statistics prove: the bus has been an extraordinarily safe means of transport for many years.

Taking a bus is safe, as is shown by the low number of fatalities in accidents involving buses. Germany is a good example: more than five billion passengers use touring coaches and service buses for urban and long-distance travel every year. Over the last 20 years, the number of bus occupants losing their lives in accidents has fluctuated between two and 36. The association of German bus operators (BDO) concludes: in no other means of transport is there a lower risk of becoming involved in an accident and suffering harm.

So it is no wonder that people place great trust in bus drivers. The market research organisation GfK has found that in Germany, bus drivers are among the top ten professions in which people have most confidence, just behind firefighters, nurses and doctors.

For the buses and coaches of the Mercedes-Benz and Setra brands, safety does not merely consist of individual measures, but is rather the result of a comprehensive, integral safety concept. The claim that stems from this approach is emphatic: these premium brands meet the highest safety expectations and drive their development work onwards in all areas.

The integral safety concept consists of several component parts. It centres on numerous innovative, vehicle and application-specific safety systems with the aim of continuously improving active and passive safety. This extends from assistance systems right up to fire alarm systems as standard equipment in all buses.

The technological safety concept is accompanied by driver training courses. Under its services brand Omniplus, Daimler Buses offers various safety training courses on customer premises or at safe driving centres. Intensive instruction familiarises drivers with the wide variety of technical systems in their bus, and their use and operation. They are then able to utilise the full efficiency and safety potential of modern buses and coaches.

It also goes well beyond this, however, including conscientious vehicle maintenance and the use of tested genuine parts in vehicle servicing.

Whether touring coaches or service buses: buses and coaches from Mercedes-Benz and Setra excel with exemplary control and operation. Their cockpits are spacious and clearly arranged, the seats, seating position, instruments and controls coming together to make for the perfect workplace. Deep-drawn windows and intelligently conceived mirror systems give the driver an excellent view.

Dynamic yet comfortably configured suspension systems, easily metered but powerful brakes, sensitive and precise steering, a surprisingly small turning circle for all model variants, smooth-running high-torque engines, convenient joystick gearshifts or perfectly configured, fully-automated transmissions – buses and coaches from Mercedes-Benz and Setra are always driver-oriented, and therefore very popular with passengers and drivers alike.

Premium touring coaches, i.e. the Mercedes-Benz Travego and the Setra TopClass 500 and ComfortClass 500, are prime examples of the practical implementation of the integral safety concept. The Electronic Stability Programme ESP is obligatory for all Daimler touring coaches. Depending on the transmission specified, most braking manoeuvres are carried out by the powerful, lightweight and wear-free secondary water retarder. The trailing axle of the three-axle buses has safe and comfortable independent wheel suspension. The optional tyre pressure monitoring system gives an early warning of tyre failure. An optional reversing camera and reverse warning device make reversing easier for the driver. On board as standard are a fire detection system for the entire engine compartment and an auxiliary heater, with a fire extinguishing system available on request. If toilets and driver rest areas are installed, these also have smoke alarms. And should an accident occur nonetheless, the driver is protected from the impact by the passive protection system Front Collision Guard, which moves the driver's seat rearwards to better preserve the survival space. Special crash elements also absorb the impact energy.

The safety technology of inter-city buses and touring coaches from Mercedes-Benz and Setra is specifically configured for their usual speeds and areas of operation. The focus here is on Lane Keeping Assist and Emergency Braking Assist, which have been available for a number of years. From the autumn these will be mandatory for newly registered touring coaches in the EU.

AEBS (Advanced Emergency Braking System) employs a radar system to detect vehicles in front as well as stationary vehicles, and continually calculates the speed difference compared to its own vehicle. If a collision is unavoidable unless immediate action is taken, the driver is first warned and the vehicle automatically initiates partial braking. If the driver fails to react and a collision is imminent, the vehicle automatically carries out a full application of the brakes. This means that the consequences of an impact can be drastically mitigated. In typical Mercedes-Benz and Setra fashion, the capabilities of AEBS already exceed those prescribed by legislation coming into force in three years in a second, more stringent stage.

Active Brake Assist 3 is even more effective. In its original form, as Active Brake Assist, it was first introduced in the Mercedes-Benz Travego in 2006 and then in the Setra TopClass 400, and has undergone continuous further development since. While AEBS drastically reduces the vehicle's speed in a critical situation, ABA 3 brakes the touring coach to a complete emergency stop when a stationary obstacle is encountered. The current Active Brake Assist 3 (ABA 3) is available for the premium touring coach series Mercedes-Benz Travego, Setra TopClass 500 and ComfortClass 500, as well as the double-decker Setra S 431 DT.

Touring coaches with ABA 3 from Mercedes-Benz and Setra therefore not only mitigate the effects of a severe accident, they are even able to prevent it within the physical limits, which makes ABA 3 an ideal assistance system. Mercedes-Benz and Setra install Active Brake Assist 3 in theo cited touring coaches as standard if the customer orders the vehicle with adaptive cruise control on whose radar system ABA 3 is based. Both brands therefore actively encourage the spread of an assistance system that can save lives.

Adaptive cruise control (ART) is the precondition for Active Brake Assist 3. It relieves the driver's workload on highways and motorways. When ART detects a slower-moving vehicle ahead, it automatically decelerates the coach until a speed-dependent safety distance preset by the driver is reached. The system then constantly maintains this distance. A radar sensor constantly scans the road ahead of the coach for this purpose. It measures the distance and relative speed of vehicles ahead, and also registers any obstacles. If there is no vehicle ahead, ART operates as a cruise control system.

With the additional stop-and-go function, ART also remains active in stop-and-go traffic and takes its lead from the vehicle in front when automatically stopping and moving off.

The Lane Assistant SPA from Mercedes-Benz and Setra uses a camera behind the windscreen to detect any tendency by the vehicle to leave the road unintentionally. It continuously monitors the distance between the coach and the marker lines at the edge of the lane. If the vehicle is about to cross the marking, the relevant side of the driver's seat starts to vibrate to warn the driver.

The Continuous Braking Limiter DBL brakes the vehicle by means of the retarder when the statutory maximum downhill speed limit of 100 km/h is exceeded. It is therefore practically impossible to exceed the speed limit inadvertently when driving downhill.

Driver fatigue is a safety risk. Attention Assist (AtAs) is able to register drowsiness at the moment of its onset, and warns the driver to take a break. The centrepiece is a sensor which recognises steering movements and their speed very precisely. This enables the system to detect early signs of drowsiness and warn the driver with audible and visual signals.

The Mercedes-Benz Citaro city and inter-city regular service bus, as well as the Mercedes-Benz CapaCity L derived from it, is not only a worldwide bestseller with more than 40,000 sold to date, but also sets the standard for safety in its class. The basis for its exemplary passive safety is a lightweight yet extremely strong framework using annular frame members with rigid door apertures and a unique frontal impact protection system – both the driver and passengers are outstandingly well protected in the Citaro. The rollover resistance of the Citaro already complies with the ECE R66-01 standard for 2017, ensuring maximum survival space for the occupants in the event of the bus tipping over.

A very unlikely event in the Citaro. It already reassures greatly with its stable, independent front suspension and precise steering. Moreover, the Citaro as a solo bus was the first regular service city bus to feature the Electronic Stability Programme ESP as an option.

The articulation joint is a major component of any articulated bus. In both the Citaro G and the large CapaCity L, Mercedes-Benz uses a standardised joint platform on a worldwide basis. The unique anti-jackknifing system ATC (Articulation Turntable Controller) newly developed by Mercedes-Benz for the Citaro G and CapaCity L is highly sophisticated. ATC sets a new standard for handling and safety in articulated buses. The ATC dynamic control system works quickly and above all to the precise extent needed to regulate the hydraulic damping of the articulated joint as a function of the steering angle, articulation angle, speed and load. To achieve this, the ATC relies on the data from the CAN databus. As a result, the joint of the Citaro G and CapaCity L is practically free-moving under normal, stable driving conditions. This optimises the cornering characteristics and steering effort, with the result that the steering forces and responsiveness of the articulated bus are virtually on a par with those of a solo vehicle. In contrast to articulated buses from competitors, there is only a slight tendency to understeer. This considerable improvement in handling also minimises tyre wear at the front axle.

Should the vehicle find itself in an unstable situation – for example in slippery road conditions – the damping of the joint is quickly adjusted to compensate as necessary. Within the physical limits the articulated bus can thus be very quickly stabilised, so avoiding any see-sawing of the rear section or, in the worst case, the dreaded jackknifing effect. The new ATC anti-jackknifing control system is thus the only system of its type to achieve anything like the effect of an electronic stability control system, and sets a new safety standard for articulated buses.

The driver is the essential component for a safe bus journey. For 21 years, under the Omniplus services brand, Mercedes-Benz and Setra have therefore offered driver training courses throughout Europe. More than 15,000 drivers have meanwhile been trained since the start in March 1993. Their number is due to increase owing to the legal requirement for professionally qualified drivers. In view of this, Omniplus has further expanded the range of training courses.

Avoiding hazardous situations is the primary aim of the Omniplus driver training courses – so that if possible, the numerous safety systems in Mercedes-Benz and Setra buses and coaches never need to intervene. Should a dangerous situation nonetheless occur on the road, the driver should be prepared to respond correctly and professionally. Whether practical exercises involving braking and avoiding action on various road surfaces and at different speeds, or detailed information about the functions and operation of bus safety features – the safety training covers a wide range of topics. The programme ranges from one-day intensive courses on the premises of bus operators, or at driving safety centres, to the premium safety training course with a duration of two and a half days.

Also available is school bus training, both for drivers and for school classes. These courses take place at the school and consist of theoretical and practical sessions that heighten the safety awareness of the children.

Other training courses include EcoTraining for economy-oriented driving, the ExpertHandling course for perfect operation of all the systems, communication courses on behaviour towards passengers, advanced training on driving and resting periods, conduct in an emergency and a course on fitness, nutrition and first aid.

In 1955 Setra was among the first to pioneer independent air suspension systems for buses and coaches. Another pioneering achievement was the introduction by Setra of the retarder as a non-wearing auxiliary brake in 1964. For its part, Mercedes-Benz already began the systematic simulation of accident scenarios in the 1960s, incorporating the results into its development work. In 1974 the Mercedes-Benz O 303 featured integrated rollover bars and energy-absorbing crumple zones. In the early 1980s it demonstrated its great stability in practical rollover tests.

In 1981 Mercedes-Benz was the first bus manufacturer to present the anti-lock braking system ABS – and Setra was the world's first brand to install ABS as standard from 1984. From 1985 the driver's workload in the Mercedes-Benz O 303 was eased by the electro-pneumatic power shift EPS – a precursor to present Mercedes PowerShift transmissions. From 1990, with the 300 series, Setra was the first brand to opt for so-called "ladybird antennae" as exterior mirrors – these afford the best possible view backwards and even ahead of the bus. In 1993 Mercedes-Benz and Setra were the first bus brands to obtain an EC R66 certification for the stability of the bus body during an accident or rollover.

In 1997, with the newly launched Citaro city regular service bus, Mercedes-Benz first introduced the electronic braking system EBS with disc brakes all-round and annular frame members for the bodywork into bus and coach engineering – these frame members ensure a lightweight yet extremely strong and safe body. At the International Commercial Vehicle Show (IAA) in the same year, Mercedes-Benz presented the "Innovisia" vehicle study to document the state of the art in safety technology and give an outlook on the assistance systems of tomorrow.

1999 saw the introduction of xenon light, wide-angle exterior mirrors with an integrated reversing aid and the driver-friendly joystick gearshift with the Mercedes-Benz Travego. In 2002 Daimler Buses was the first manufacturer to offer the Electronic Stability Programme ESP for its Travego touring coach, and in 2003 it entered series production in the Travego and Setra TopClass 400. Since 2006 ESP has been standard equipment for all the touring coaches of both brands. Other milestones include proximity cruise control and the Continuous Braking Limiter in 2005, and the Lane Assistant for touring coaches in 2006. In 2006 the Mercedes-Benz Travego Safety Coach showed all the then available safety systems for the first time.

Whether with the emergency braking system Active Brake Assist, with side reversing spotlights as a manoeuvring aid or with passive safety features such as the Front Collision Guard – the Mercedes-Benz and Setra brands are always ahead of the field.

The capabilities of safety and assistance systems are best experienced in practice. Buses and coaches from Mercedes-Benz and Setra will therefore be demonstrating their extraordinary abilities with spectacular manoeuvres at the Safety Campus.

The Mercedes-Benz Travego with signal yellow paintwork as a demonstration safety coach will present Active Brake Assist 3 with an autonomous emergency braking manoeuvre from full speed when confronted with a stationary obstacle. Visitors will be able to experience the capabilities of the electronic stability system ESP and the Lane Assistant SPA with a Setra TopClass S 516 HDH. Exercises with the Mercedes-Benz Citaro city regular service bus will show that ESP is also useful in a city bus. Mercedes-Benz will use the 21-metre long CapaCity L to demonstrate the action of the anti-jackknifing system ATC – this will undoubtedly be a particularly spectacular exercise in view of the sheer mass of this large-capacity bus.