Expansion speed

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The expansion speed is a technical term used throughout the German-speaking area from the transport sector and a special expansion value . Expansion values ​​are parameters that describe a traffic route and are therefore a measure of the condition of the traffic route. The expansion speed describes the maximum possible safe traffic speed on a traffic route. Expansion speed is not the same as cruising speed . Travel speed is the ratio of the distance between the starting point and destination and the total travel time.

application

The expansion speed is given for existing traffic routes. In road construction , the speed of expansion shows whether speed limits are necessary. If the quality of a route suffers due to aging or excessive loads, the expansion speed may have to be adjusted downwards. In the case of new construction projects, however, minimum values ​​are set for the expansion speed. The route planning must then be carried out in such a way that the required minimum expansion speed is achieved.

parameter

The expansion speed is always considered from the point of view of traffic safety . It depends on various parameters. The two most important for all traffic routes are the minimum curve radius and the maximum gradient , as well as the static friction of the rolling parts and the clarity of the route (see also braking distance ) , especially in road and track construction . However, the safety devices of the vehicles also play a major role (see also driver assistance systems ).

The rate of expansion also depends on the environmental conditions (e.g. wetness, wind). Modern traffic control systems adapt the current maximum speed to the current environmental conditions. The known conditional speed limits (e.g. signs 60 km / h when wet) take this fact into account.

The achievable expansion speed is directly dependent on the structural and landscape framework conditions of the traffic route. The highest expansion speed is achieved on a straight, level stretch. Obstacles that influence the route and thus the speed of expansion are, for example, elevations, depressions, bodies of water , settlement, nature or landscape protection areas or existing traffic routes. When planning traffic, aspects of environmental protection must then also be taken into account.

Further meaning

The term expansion speed is also used in its trivial meaning as "speed of expansion". In this context, it also appears as a qualitative parameter outside of the transport sector (such as expansion of childcare places , expansion of a residential building , expansion of structures in real-time strategy games )

See also

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