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PIARC (World Road Association), founded in 1909 and comprising 125 member governments from all over the world, is the global forum for exchange of knowledge and experience on roads, road transport policies and practices. With consultative status to the Economic and Social Council of the United Nations, the Association is contributing to a stable and sustainable global development of the road and transport sector.

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Term of the Road Dictionary

clear zone

  • Language : PIARC Road Dictionary / English
  • Theme : Roads Design Components of the Road
  • Definition : Area adjacent to the traffic lanes that should be kept free from features that would be potentially hazardous to out-of-control vehicles. Notes:
    1. The clear zone is a compromise between the recovery area for every errant vehicle, the cost of providing that area and the probability of an out-of-control vehicle encountering a hazard.
    2. The clear zone should be kept free of non-frangible hazards where economically and environmentally possible. Alternatively, hazards within the clear zone should be treated to make them safe or be shielded by a safety barrier.