How Expressway Characteristic Factors Contribute to Accident Counts

Logistic regression and statistics are combined to analyze accident-related data collected from the “Traffic Accident Database System” (TADS) in order to find the relationship between expressway characteristic parameters and accident rate in a mountainous area. A total of 2,004 observations are used to illustrate the proposed model. A new concept average corner (AC) is also introduced to evaluate the effect of horizontal alignment. Accident rate (the dependent variable) in this study is a dichotomous variable so a binary logistic regression is found suitable. In total, sixteen variables are put forward and fourteen are used in the model. Eight variables are found to be significantly associated with the accident rate at the 0.05 significance. Each of variables is interpreted with the results of Spss 19.0. The findings show that the logistic regression and the statistical method used in this paper are a powerful forecasting tool and can be applied to the further studies. After the analysis, some valid measures are taken to reduce the accident rate of expressway in mountainous area.