The Selection of Optimal Probability Distribution and Estimation for Design Hourly Factor in National Highway Roads
Jun-Han Jo, Jong-Hyeon Han, Seong-Ho Kim, Byeong-Saeng Lee · Journal of the Eastern Asia Society for transportation studies/Journal of the Eastern Asia Society for Transportation Studies · 2006
This research is to the selection of optimal probability distribution as well as the estimation for design hourly factor in consideration of traffic characteristic, such as road function, lane number and AADT. To accomplish the objectives, we are applied to various probability distribution using traffic data that observed at permanent traffic count points in 2005. The parameters or the selected 14 probability distribution were estimated based on the method of maximum likelihood and the validity condition of the estimated parameter The goodness-of-fit test, such as chi-square test. was performed as well as the estimation of design hourly factor. As a result, An appropriate distributions of each case were selected : Pearson V for two lane of rural roads, LogLogistic for the four lane of rural roads, LogLogistic for the urban roads, Extreme value for recreation roads. And optimal K factor are as following : for two lane of rural roads, for the four lane of rural roads. for the urban roads, for recreation roads.