Traffic barrier

A guardrail (colloquial and technical language also outdated guardrail, guardrail in Austria ) is a passive protection device ( restraint system ) of metal (usually steel or aluminum partly ) on roads. It serves mainly to prevent the agreement of a vehicle off the road and protect areas outside the roadway in front of a vehicle impact.

Original idea

Exceedances of the outer road boundaries, whether marked or unmarked, counted since the advent of road transport, and later the automobile traffic of the most common hazards. However, they resulted in the large number of incidents rarely an accident, thereby reducing the risk is subjectively reduced perceived by the driver. While driving a possible accident mainly by the probability of its occurrence, but less by the anticipated severity of its consequences is evaluated. This was especially visible in motor sport, which is performed at high speed with a steadily increasing pressure of time and who anticipated the general development of the road as an example. With some historical exceptions initially guardrails were in motorsports introduced across the board, which were positioned at locations with expected serious accidents, including outer curves on slopes, roads with tree plantings and in places with higher Zuschauerfrequentierung. From the perspective of the driver initially a predictable, visually detectable as well as obstacle and in the event of an accident created a physical barrier that protects the vehicle from heavier damage as it occurs on falling in ravines or on contact with vegetation. In conventional road transportation safety barriers initially banked by at special hazards. Today, a large part of many roads is secured with safety barriers, as well as on highways, the default both directions away from each other - sometimes in the form of massive installations of concrete, which offer greater protection against traffic. With increasingly further spread of this protective device is being discussed today especially about the most appropriate form. At the bottom of closed installations are often considered safer, but are often more expensive to buy and can therefore only be provided in smaller numbers.

Statistically lead guardrails in certain driving styles to frequent damage, but the limited primarily to minor scrapes and light body damage. The number of serious accidents, however, is a seites by the physical barrier, but also reduces the learning behavior by the driver ( learning from mistakes and learning on the example ) because the road boundary is taken more seriously in anticipation of expensive property damage.

The introduction of barriers on the West German motorways began in the early 1960s.

Function and construction

Safety barriers contribute to the prevention of serious accidents. For example, if a motorist falls asleep, hits its first vehicle to the crash barrier, which is designed to prevent that it gets ( existing behind the guardrail ) obstacle to another.

Mostly guardrails are made ​​of steel. In Austria a long time was used for aluminum guardrails; later they used steel here. The reason why aluminum was used in Austria for safety barriers, is that the Austrian State operating an aluminum plant in Ranshofen that could produce the aluminum guardrails cheaper. Steel compared to aluminum for safety barriers but clearly more suitable, because it can withstand higher forces and therefore dimensionally stable. The stability is determined by the particular profile of the guardrail (profile A [ Armco ]; profile B [ Bethlehem ] ) still increased and special shapes (Safety Rail or super - Rail). Guardrails are usually galvanized, to protect them from corrosion.

Problems and alternatives

The use of safety barriers in its present form is seen particularly critical of motorcyclists. Even when dropped at low speed, it may come to slip under the plank and by snagging the post serious injury. Typical are here amputation injuries in the worst cases leading to a Beheading. Such injuries are also possible when slipping lower sports car, the impact with the guardrail especially in convertibles even at low speeds much higher personal injury after runs as if no barrier were present. Improvements can quite easily be done by attaching a rear underrun protection, but this is not implemented nationwide in Germany. This protection would be achieved either with a second, parallel low -mounted plank ( plank pendulum ) or specifically for motorcyclists by low-cost thick foam jackets ( crash absorbers ) of the posts. This tries to reach the club MEHRSi by working with sponsors and the relevant authorities.

The height of the guardrail can not always prevent trucks can get over them or through them. Even the duplication of the middle guardrails can not keep on his trail a fully loaded truck. A concrete barrier can of trucks regardless of the impact angle is not to be broken. For passenger cars, but it is because it does not yield when force is applied, much more dangerous. Has an impact on a concrete bulkhead severe deformation of the body and high acceleration forces on the occupant result. A guardrail absorbs kinetic energy and absorbs it through its own deformation; a concrete barrier can not. The bouncing back and skidding of a car is therefore stronger for her.

To achieve higher safety for these road users, is part of the current accident research.

Norms and Standards

Prior to the approval of a guardrail system, this has to go through the tests according to EN 1317-1 to 1317-4 restraint systems on roads and to exist.

  • Guidelines for passive protection on roads by vehicle restraint systems (RPS )
  • Additional technical terms of contract and guidelines for passive protection devices ( ZTV -PS)
  • Technical delivery conditions for steel guardrail (TL -SP 99)
  • Quality and testing for vehicle restraint systems on roads made ​​of steel - steel guardrail systems (RAL -RG 620)
  • Technical delivery conditions for guard rail posts sheaths (TL- 93 SPU )
  • RVS 05:02:30 - restraint systems
  • RVS 08:23:05 - rails made ​​of steel ( May 2005)
  • RVS 15.04.71 - Road Restraint Systems (October 2009)
  • SN 640 561 - Passive safety in public space; Vehicle restraint systems
  • SN 640567-1 - restraint systems on roads - Part 1: Terminology and general criteria for test methods
  • SN 640567-2 - restraint systems on roads - Part 2: Performance classes, impact test acceptance criteria and test methods for protective devices
  • SN 640567-3 - restraint systems on roads - Part 3: Performance classes, impact test acceptance criteria and test methods for crash cushions
  • SN 640567-4 - restraint systems on roads - Part 4: Performance classes, impact test acceptance criteria and test methods for start, end, and transition of safety barriers
  • SN 640567-5 -NA - Requirements for restraint systems on roads - Part 5: Product requirements, compliance procedures and certification for vehicle restraint systems
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