Lim, K. K. and Kim, S. G. (2006). “The classification of railroad accident types and its standardization.” Journal of the Korean Society of Civil Engineers, Vol. 26, No. 1D, pp. 133-140 (in Korean).Lim, K. K. and Kim, S. G. (2006). “The classification of railroad accident types and its standardization.” Journal of the Korean Society of Civil Engineers, Vol. 26, No. 1D, pp. 133-140 (in Korean).