At present, many countries have adapted Traffic Impact Analysis (TIA) to assess the additional demands for road capacity imposed by new developments. This article discusses when such a traffic impact analysis is needed, and what factors should be considered in the study. The factors relate to the issues involve the geographic area of study; time frame for the phases of the project; non-site traffic; programmed transportation improvements; study methodology; and analyses and recommendations. The main purpose of the study was to put forward diffusion model that decide the geographic area of study, which adapt to different types of developments and different development size. The model is founded according to site traffic dissipative character and based on the principle of synergetic theory, one of System theory. The model found the biggest study area function on the condition of different traffic impact extent around road network of new developments, and then validate this model by how to decide the study area of Beijing Legend science zone. The model makes up for the disadvantage that local officials and highway agencies decide the geographic area of study arbitrarily. The objective of the model is to develop a more efficient and understandable means, by which the traffic impact of a new or expanded development can be identified, coordinate the relationship between land uses and road supply.
Abstract