Analysis Of The Impacts Of Meteorological Conditions On Road Traffic Accidents

Adverse weather conditions is one of the key factors causing traffic accidents and the research of traffic meteorological disasters had became one of the hot issues at home and abroad both in the fields of traffic and meteorology. Based on the data of the monthly traffic accidents and the observed monthly meteorological data (including precipitation, temperature, visibility, pressure and relative humidity) covered the roads of Nanjing Region from January2010to December2012. Statistics Package for Social Science (SPSS) was used in this paper to analyze the relationship between the daily road traffic accidents amount and the meteorological factors influenced the occurrence of road traffic accidents.The paper analyzed the proportion of the traffic accidents occurred under different meteorological conditions, the three factors which have major influence on traffic accidents were found using principal component analysis according to the features different meteorological conditions, the three factors were daily precipitation, averaged temperature and visibility. The paper established the automatic regression (AR) models and the stepwise regression (SR) models to describe the relationship between the amount of traffic accidents and meteorological factors according to the three factors, and briefly analyzed the impacts of these factors on the occurrence of road traffic accidents. The results showed ad follows:(1) the amount of daily traffic accidents during the weekdays was positively correlated to the daily precipitation, and negatively correlated to the daily mean temperature in both models, and the results of both models passed the significance test at0.05. While the correlation between the daily minimum visibility and the amount of daily traffic accidents was not significant (a=0.266). In the non-work days, the correlations between the amount of daily traffic accidents and the daily precipitation, the daily mean temperature and the daily minimum visibility were not significant.(2) The stratification analysis on the daily precipitation, the daily mean temperature and the daily minimum visibility showed that the correlation between the precipitation and the amount of traffic accidents was gradually reduced with the increase of the magnitude of precipitation; The daily amount of traffic accidents was negatively correlated to the daily mean temperature when the daily mean temperature was between2℃to12℃. The amount of daily traffic accident was negatively correlated to daily minimum visibility when the daily minimum visibility situated wad between200-500m.(3) The results of goodness of fit showed that the AR model (the result of the goodness of fit was equal to0.868) had a better fitting effect than the stepwise regression model (the result of the goodness of fit was equal to0.729) during the weekdays.The paper analyzed the effect tests to the traffic accidents from January to December2013according to the automatic regression, it was found that the AR model had a better predicting accuracy to the amount of traffic accidents during weekdays, the overall accuracy was up to0.7831. During rainy days, the predicting results was good, as well, especially at the beginning of the rainy days, the relative error was less than0.05,While the predicting capacity was relatively poor when it was in freezing rain and snow weather.