Engineering Method for Calculating Changes in the Structure and Intensity of Traffic Flow

Abstract

The real costs of the population caused by pollutants emitted by motor vehicles operating on the roads of cities of the Russian Federation are directly related to the intensity and structure of motor vehicle flows. The paper solves the scientific and practical problem of reformatting the data of instrumental online monitoring of the intensity and structure of motor vehicle flows on the street and road network of St. Petersburg into numerical information, adapted to the program for calculating the expected air pollution with pollutants emitted by road traffic for conditions of extremely dangerous vulnerability of the urban population. The conditions of extremely dangerous vulnerability of the urban population are determined by a combination of unfavorable meteorological factors for the dispersion of pollutants with hours of maximum traffic load (rush hours of automobile traffic). An engineering technique for calculating changes in the structure and intensity of motor vehicle flow and an original program for its implementation by means of MS Excel are presented. New statistical patterns of changes in the intensity of motor vehicle flows for typical highways and streets have been obtained, which make it possible to reliably predict in real time the local situations of extremely dangerous for the urban population air pollution with pollutants emitted by road traffic. Computational study, using the developed methodology, found that on the most loaded ring line in St. Petersburg in the vicinity of the cable-stayed crossing "Obukhovsky Bridge", under unfavorable meteorological conditions during rush hours it is likely to expect a multiple excess of the maximum permissible standards for dioxide nitrogen NO2 (up to 10 MACMOT). The calculation method efficiency has been confirmed when solving specific problems of urban motor vehicle flow management under extreme meteorological and road conditions.