Citation

Beak TH, Lim JK, Park BH. KSCE J. Civil Eng. 2015; 19(4): 1097-1107.

Copyright

(Copyright © 2015, Holtzbrinck Springer Nature Publishing Group)

DOI

10.1007/s12205-015-0100-2

PMID

unavailable

Abstract

This study deals the relations between operational method and traffic accident of circular intersection. The purposes are to identify the difference of safety according to operational methods (rotary and roundabout) and to develop the traffic accident models. In pursuing the above, this study gives particular attentions to testing the hypothesis of difference between the above methods and developing the appropriate models which can represent the difference. The main results are as follows. First, the hypothesis test shows that roundabout and rotary have different number of total accidents and severe accidents, which are analyzed to be reasonable at 0.05% level of significance. Second, 2 multiple linear regression models are developed, which are all statistically significant. The independent variables in the number of total accidents are analyzed to be traffic volume, acceptance ratio, yield line, stop line and signal, and the independent variables in the number of severe accidents are evaluated to be traffic volume, acceptance ratio, yield line and signal. Third, 2 negative binomial regression models are selected as the most appropriate models, with the likelihood ratios of 0.412 and 0.322. Fourth, in the case of the number of total accident models, a negative binomial regression model is analyzed to be more appropriate than a multiple linear regression model. In the case of severe accident models, however, a multiple linear regression model is evaluated to be more appropriate than a count data model. Finally, the selected variables in the developed models are very important variables for classifying the operational methods. The signs of independent variables also present the difference in safety between roundabout and rotary. In particular, the variable of acceptance ratio presents negative (−) sign and the variables of stop line and signal present positive (+) signs. The more acceptance ratio represents the characteristics of roundabout, and the stop line and signal represent the characteristics of rotary. Therefore, the above developed models show that roundabout is much safer than rotary.

Language: en