Road traffic

The road traffic ( Anglicism: road traffic ) is the displacement of motor vehicles on a Route.

Its knowledge, so much in terms of quantity than of nature, is useful in various fields.

Measure

One measures it by counting the number of vehicles for one period of time. The units most employed are the number of vehicles per day and the unit of the “30e hour”. The latter represents the level more requested section of the roadway studied in one day. The 30e hour is the 30e hour the most requested in circulation during one hour for the one year period. She is regarded as the peak period.

Roadway system

The originator of Voirie determines the number of ways according to the volume of circulation. To take into account the various types of Vehicle S, it often uses the unit of particular vehicle (UVP) definite as follows:

a light vehicle or a van = 1 UVP
heavy trucks of 3,5 tons and more = 2 UVP
a cycle = 0,3 UVP (exceptionally between 0,2 and 0,5)

The engineering of the traffic distinguishes the flow from a way (which varies one moment of observation to the other) and the capacity, which represents the maximum flow (and which is thus an invariant for a state of the roadway system).

The flow of a way depends on the mean velocity of circulation because, with raised pace, the drivers increase the interval between vehicles. It also depends on the degree of attention of the drivers. Thus, on the urban fast tracks like the ring road of Paris, the interdistance is weaker than on a road of close-cropped countryside; but one could not preserve the degree of concentration a long time only that asks. Under normal conditions, the flow of a way reaches its maximum for a flow of vehicles circulating approximately to 50 km/h.

One can, concerning the capacity, to retain the orders of magnitude according to:

5 000 with 7 000 UVP/jour for a two-track road, in open country,
10 000 with 13 000 UVP/jour for a four-lane road without central reservation,
13 000 with 18 000 UVP/jour for one twice two ways and Crossroads S on level,
30 000 UVP/jour for a highway with twice two ways and crossroads uneven (but 60 000 UVP/jour in perish-urban zone).

The traffic determines also the constitution of the Chaussée. The nature and the thickness of the wearing course depend on the volume of circulation while the body of Chaussée is dictated by the number of Heavy truck S.

Noise

Urban installation must take into account the level of Bruit generated by the road infrastructures, railway or air. Into France, one divides the infrastructures in five classes of noise which determine the levels of soundproofing that the building S neighbors must respect.

Transport

The development of a Plan of urban displacements also requires a good knowledge of the road traffic, but this data is not enough. It should be supplemented by investigations origin-destination .

See too

Internal bonds

External bonds

of January 9th, 1995 and decree of May 30th, 1996 relating to the classification of the terrestrial transport infrastructures in France.
Road traffic in real-time for the Ile de France
: road traffic in India. Not easily believable.

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