Physiological safety: safe and relaxed driving in the new S-Class
Practical scientific testing confirms that the psychophysical stress experienced by drivers travelling long distances in the new Mercedes-Benz S-Class is lower than in other vehicles. The intelligent overall vehicle concept and state-of-the-art technology of these luxury-class saloons reduce driver workload, help to prevent stress and thus have a positive effect on driver fitness. Thus as well as improving personal wellbeing, the first-class comfort and convenience of the new S-Class models also contribute to enhanced road safety.
Physiological safety was one of the main aims of safety development work on the new S-Class, alongside occupant protection and safe handling. The Mercedes engineers sought to design a car which would not adversely affect but would in some cases even improve the driver’s psychophysical fitness, thereby helping him to focus on traffic conditions and, by conserving his energies, allowing him to respond safely and confidently in critical situations. Key factors in physiological safety include intelligent dimensional design, first-class ergonomics, good seating comfort and climate comfort and low noise levels.
Long-distance driver-monitoring tests by the DaimlerChrysler Research department involving more than 20 car drivers confirmed that the new S-Class offers a very high standard of physiological safety. On the route Berlin Leipzig Dresden-Berlin, the researchers monitored typical stress indicators and performed online status checks on the subjects’ emotional mood state. They also carried out psychoanalytic interviews before and after each of the five-hour drives.
The comparison test between the S-Class and competitor models on the approximately 500-kilometre route confirmed the influence of state-of-the-art vehicle engineering on heart rate, an important stress indicator. Under identical driving conditions and traffic conditions, the average heart rate of drivers was up to six per cent (or five beats per minute) lower in the Mercedes than in the vehicles it was compared with. In the opinion of the researchers, this is a clear indication that the range-topping Mercedes model provides high standards of stress-relieving comfort.
The new long-distance test also confirms the significant progress made by Mercedes-Benz in the field of physiological safety over the past 15 years. The heart rate of drivers in the new S-Class was up to eight per cent (or 6.8 beats per minute) down on the reading recorded in past tests with the W 126-series S-Class.
Intelligent overall vehicle concept is key to high physiological safety
A range of technical innovations in the new S-Class are key factors in ensuring a very high standard of physiological safety. The smooth-running high-torque engines, the comfortable, optimally isolated air suspension, the low-vibration body, the intelligent vehicle control and operation system and the spacious, ergonomically designed interior play a major part in keeping drivers fit and alert. Significant contributions are also made by the newly developed twelve-way adjustable seats and an interior climate which remains agreeable in all driving and weather conditions, thanks to the sensor-controlled THERMOTRONIC climate control system.
As regards interior dimensions, the Mercedes engineers followed a simple rule of thumb: the vehicle must adapt to its driver, and not vice versa. With this in mind, and taking into account scientific research findings, they developed an interior whose space concept and ergonomics are designed to offer passengers an optimal impression of space, optimal room in all directions and optimal long-distance ride comfort. With a length of 5076 and 5206 millimetres, the body of the new S-Class is 33 and 43 millimetres longer than the standard and long versions of the previous S-Class. It is also 16 millimetres wider and 29 millimetres higher. The wheelbase has been increased by 70 and 80 millimetres, depending on version, to 3035 and 3165 millimetres.
The occupants see the benefits of these larger dimensions in terms of greater spaciousness and comfort. Shoulder room and elbow room have been increased by up to 39 millimetres, while headroom has increased by up to 5 millimetres. Effective legroom, an important requirement for seating comfort, has increased by five millimetres for the driver and front passenger and by 24 millimetres for rear-seat passengers. In the long-wheelbase version, the increase for the rear-seat passengers is a full 52 millimetres.
Assistance systems for stop-and-go traffic, nighttime driving and parking
Innovative assistance systems now making their world debut in the S-Class provide additional stress relief for the driver, along with enhanced safety and convenience. The DISTRONIC PLUS proximity control system now operates throughout the speed range from 0 to 200 km/h. In stop-and-go traffic, DISTRONIC PLUS maintains a safe following distance from the traffic in front, automatically braking the S-Class to a standstill when necessary and accelerating back to the desired speed when the traffic starts moving again. In this way the system promotes stress-free driving and significantly enhances physiological safety.
Also new is the radar-based Park Assist system, which provides assistance during reverse parking and manoeuvring. This system not only allows the driver to park with centimetre precision, it also warns of obstacles as far as eleven metres away. In the dark, an innovative night view assist system provides enhanced active safety. It extends the driver’s range of vision significantly, allowing him to spot pedestrians, cyclists, parked cars and other obstacles much sooner than would otherwise be the case.
Scientific monitoring of physiological safety began more than twenty years ago
Physiological safety is an integral part of the integrated Mercedes safety philosophy PRO-SAFE. A key component of active safety, it focuses on the medical and psychological aspects of driving and plays an important part in preventing accidents.
Mercedes-Benz has been carrying out driver-monitoring tests in this field, in association with the DaimlerChrysler Research department, since the early nineteen-eighties. No other brand in the automotive industry has devoted as much attention to this field of development as Mercedes-Benz. The studies allow in-vehicle systems in Mercedes models to be objectively evaluated, while at the same time potentially highlighting areas where assistance systems of the future could further improve cooperation between driver and vehicle and help to conserve the driver’s physical and mental energies.
The new S-Class has profited from the researchers’ and developers’ extensive experience in the field of physiological safety. In this area too, it fulfils its role as a pacemaker in the automotive industry.