Estimating Number of Accidents in Intersection According to Relation between Traffic and Geometric Variables (The case study of Tehran City)

The economic development of societies affected by transportation industry. All of the countries that start development must make the facility of transportation. This developing without of developing of human factors, vehicles and environment may not be occurring. Not development in these cases may accidents that can eliminate the economics of society. So, collection and analyze the accidents data is base design plans for reduce the accidents and their recompense. Recentllty, some studies in modeling of accidents in and out of cites was developed according of traffic flow, situations of geometric plan, environmental and road circumstance. Because of high number of accidents in junction in Tehran, this assay analyze the effected factors on safety in these junctions and try to makes a statics model for estimate number of accidents and improve of traffic flow. In the research method, the selected junctions in Tehran were compared according to accidental place and most of them selected for more study. Then, the effected variables in accidents according the data in model and selection were determined. As a result, the survey according to equal between data mean and data variance, in two sentence negative and plus from correlation coefficient is better than linear Poisson (LP) cascade model.