Abstract: Aiming at the defects of the traditional method of computing the leftturn vehicle traffic capacity, the existing model for the gap acceptance at the intersection without traffic signal was improved and a new model was developed for the leftturning crossing the opposite through vehicles with limited priority. The proposed model was calibrated by the field data, resulting in that the critical gap of the left-turn vehicles is 3.4 s. The leftturn vehicle traffic capacity was computed with the gap. Compared with the traditional model, the proposed model appears closer to the reality, its average relative error is 16.47%.

Key words: road transportation engineering, two-phase intersection, limited priority, traffic capacity, critical gap