THE EFFECT OF TRAFFIC-CONTROLLING AND TRAFFIC-INFLUENCING MEASURES ON THE EMISSION OF NOISE BY ROAD TRAFFIC

An attempt has been made to produce a to describe and determine the emission of noise by road traffic in which the parameter of the traffic is used as the input value rather than a characteristic value obtained from the consideration of traffic as the movement of a number of single vehicles. For this purpose a regression analysis statement was used in which the equivalent continuous sound level is represented as a function of the variable kinetic of the traffic flow and of the traffic mix. This model, which by reference to the laws of hydrodynamics for the idea of movement serves not only for the description of traffic but also as a basis for noise emission, is designated as an energy model and by a series of survey measurements has been confirmed and quantitatively supplemented. With the aid of this the effects of traffic controlling or traffic influencing measures or various road design factors upon the parameters of traffic may be used directly for estimating the consequential changes in noise emission. The area of validity of the covers stable traffic flow, but can be extended for conditions of unstable traffic. By this means it is possible to classify changes in noise levels from temporarily overloaded sections of road in comparison to the behaviour of freely flowing traffic. The increase in noise levels in the vicinity of approach roads to signal control intersections has been particularly considered and as a result of survey results a relation with the number of waiting vehicles has been derived. By this means it is possible to directly indicate and evaluate the influence of strategies of signal control for the achievement of optimum traffic upon the value of noise emission. (TRRL)