In 1951 Daimler-Benz filed a patent entitled “Motor vehicles, particularly for the transportation of people.” This referred to nothing less than the invention of the crumple zone. It was a patent which was to revolutionize bodywork engineering throughout the entire automobile industry in the coming decades. The ingenious originator of this idea was Béla Barényi, who was not at all impressed with the prevailing maxim that “a safe car must be robust and not unstable.” He was the first to recognize that kinetic energy occurring during an impact must be absorbed by deformation to protect the occupants. Accordingly he divided the vehicle body into three logical zones: a soft front end, a rigid passenger cell and a soft rear end. Patent DBP 854 157 was granted on January 23, 1952.

The year 1953 marked a break from tradition and entry into the modern age of Daimler-Benz car design, with the appearance of the 180 as the direct successor to the 170 series which had been in production for 17 years. The 180 was the first Mercedes-Benz with a self-supporting three-box body. This had considerable advantages over the previous design, not only in the utilization of the base area. The bodywork concealed the sensational new frame/floor unit, a load-bearing platform consisting of box sections with connecting sheet-steel panels, which supported all the major assemblies and was welded to the bodywork to form an entity. The advantages of this design were greater rigidity, approximately 70 kilograms less weight versus a frame-type construction, and improved lateral stability.

The crumple zone patent was followed by years of basic research. Barényi’s invention was developed to production standard at Daimler-Benz. The W 111 series launched in August 1959 – the Mercedes-Benz 220, 220 S and 220 SE – went down in automotive history as the world’s first production cars with integral crumple zones and high-strength passenger cell. The so-called fintail model also boasted other innovative safety features. A particularly conspicuous feature was the interior designed to reduce injury hazards: hard, sharp-edged interior fittings and controls had disappeared to be replaced by recessed door handles, a dashboard yielding on impact, padded window surrounds, window winders, armrests and sun visors, and a steering wheel with a large impact-absorbing boss. The rear-view mirror was designed to detach from its bracket under a severe impact.

Mercedes-Benz first announced seat belts in 1957 for the 300 SL roadster (W 198 II). In 1958 the new restraint system was offered as an optional extra first in the sports car, then in all cars with individual front seats. The first models were two-point lap belts; two-point diagonal belts followed in 1962. From 1961 all Mercedes-Benz cars were fitted with anchorage points for seat belts on the front seats; from 1962 also with anchorage points in the rear. In the late 1960s the three-point seat belt, a combination of lap and shoulder belt, finally established itself as the definitive form of the seat belt for passenger cars. An automatic belt retractor function was added to make it an automatic (inertia-reel) seat belt. In 1973 Mercedes-Benz introduced this seat belt as standard equipment on front seats; in 1979, three-point seat belts also were fitted to the rear seats as standard. Thanks to design details like the three-stage belt height adjustment in the S-Class, the safety system could be adapted to the passengers increasingly better to enable it to develop its maximum effect in a collision.

The airbag had its world premiere in 1981 in the Mercedes-Benz S-Class W 126. The design engineers of the Stuttgart car maker researched this revolutionary restraint system for 13 long years. The new airbag protected the driver from the consequences of a severe accident by inflating a fabric bag within a fraction of a second after a crash to absorb the impact of the driver’s body against the steering wheel. Mercedes-Benz did not replace the seat belt with the airbag, but combined both features to create an effective restraint system. This was underscored by the introduction in 1981 of a novel belt tensioner (standard equipment as of 1984) which enhanced the effect of the seat belt in an accident. The driver airbag, fitted as standard in all Mercedes-Benz passenger cars since 1992, was followed by the front passenger airbag (introduced in the S-Class in 1987, standard in all model series from 1994) and further systems like the side airbag and window bag.

The entire range of safety developments again and again manifests itself in new Mercedes-Benz models. For instance, in the new Mercedes-Benz C-Class, which featured a safety concept ranging from accident prevention through to the greatest possible occupant protection in the event of severe collisions. With the introduction of the new E-Class in 2002, these were followed by further developed intelligent restraint systems which are able to adapt to accident severity even more precisely thanks to additional sensors. The adaptive front airbags with two-stage gas generators are now joined by new, high-performance belt tensioners, two-stage belt force limiters, automatic weight recognition for the front passenger and a rollover sensor.

The Mercedes-Benz design engineers continuously improve the high safety level of their automobiles. An epoch-making step towards greater safety was the world premiere of the anti-lock braking system (ABS) in the Mercedes-Benz S-Class W 116 in 1978. With this assistant system, developed jointly with Bosch, the car remains fully steerable even during drastic braking. With conventional brakes the wheels lock up in cases like this and cease to transmit lateral forces, with the result that the car, no longer steerable, goes into a skid. ABS prevents this loss of control: during brake application the system, using wheel rotational speed sensors, checks every single wheel, and when a wheel locks up, briefly releases the brake pressure. ABS has been a standard feature of all Mercedes-Benz models since 1992.

Mercedes-Benz introduced more assistant systems for enhanced active safety in the 1990s in the form of ESP®, BAS, ABC and DISTRONIC. In 1995 the Electronic Stability Program ESP® premiered in an S-Class of the W 140 series. ESP® selectively decelerates individual wheels in critical handling situations and reduces the engine output to stabilize the vehicle. The system checks the vehicle behavior based on the data from a yaw rate sensor and measurements of the wheels. Depending on the situation and the requirements, ESP® then brakes one or more wheels and throttles back the engine torque. Since 1999 all passenger cars from Mercedes-Benz are equipped with ESP®.

The Brake Assist (BAS) interprets the driver’s braking behavior and builds up the full braking force automatically when it recognizes a panic braking situation, even if the driver applies the brakes cautiously. Introduced in 1996, this development is based on the finding of Mercedes-Benz accident research that motorists, though they do apply the brakes quickly in critical situations, do not step on the brake pedal with sufficient force.

Active Body Control ABC was introduced in 1999. This active springing and damping system automatically adjusts the suspension setting to the driving situation at hand, reducing and optimally damping vehicle body motions according to need when driving off and during cornering and braking. High-pressure hydraulics, a fast computing unit and a system of sophisticated sensors ensure a stable body position in all handling situations; ABC almost completely suppresses the pitching motions which occur at times during acceleration or braking, as well as the roll on bends.

DISTRONIC also was presented in 1999. With this proximity control system Mercedes-Benz extends the functions of the Tempomat/cruise control: DISTRONIC automatically maintains a constant distance between the car it is installed in and other road users, measuring the distance to vehicles ahead by means of an internal radar unit and comparing this value with the car’s own speed. DISTRONIC computes its response based on this data, maintaining or reducing speed. The next stage in the evolution of the system was DISTRONIC PLUS, introduced by Mercedes-Benz in 2005 in the S-Class W 221. DISTRONIC PLUS works in combination with Brake Assist Plus and covers a speed range from zero to 200 km/h. Even in slow-moving traffic DISTRONIC PLUS maintains a constant interval to the vehicle ahead and brakes the car, if need be, to a full stop.

In the 1990s, safety development at Mercedes-Benz increasingly combined passive and active elements and relied on communication between vehicles. The 2005 S-Class W 221 embodies the current status of these networked systems for integrated safety. In this vehicle Mercedes-Benz introduced its innovative safety philosophy PRO-SAFE™, made up of the elements PERFORM-SAFE (active safety, handling safety, perceptual safety and stress-reducing safety), PRE-SAFE® (preventive safety systems which “anticipate” to mitigate the effects of an accident), PASSIVE-SAFE (passive safety, interior safety) and POST-SAFE (assistant systems designed to prevent further damage occurring after an accident). In 2007, the term PRO-SAFE™ and its four elements are replaced by the designation "Integral Safety Concept from
Mercedes-Benz".

Mercedes-Benz unveiled the PRE-SAFE® safety system as early as in 2002. In the event of panic braking or in critical driving situations the system prepares the passengers as well as possible for an accident: when PRE-SAFE® detects signs of an approaching accident through the information from the ESP® and BAS sensors, the mechanical seat belt tensioners are pretensioned by electric motors, the seat and backrest are placed in a particularly secure position, and the sunroof and windows are closed. The PRE-SAFE® concept is based on the results of Mercedes-Benz accident research, which found out that in more than 60 percent of all accidents there is sufficient time to initiate preventive protection measures prior to the actual impact.

Further innovations for integrated safety premiering in 2005 in the S-Class W 221 were brake lights which pulsate during emergency braking, and the night view assist. The novel night view assist uses infrared headlamps which illuminate a far larger portion of the roadway in the dark than low-beam headlamps. The enhanced night image is shown on the instrument cluster display.

In 2006 the PRE-SAFE® brake came on the market in the S-Class and CL coupe. When the sensors integrated in the vehicle’s front end detect the acute risk of a rear-end collision and the driver fails to react, then the system will automatically perform a partial braking, thereby reducing the potential collision force and accident severity considerably.