선형의 속도/밀도모형을 이용한 도시고속도로 진입램프 접속부의 용량평가에 관한 연구

Abstract

Urban freeway means a high-speed and high-volume network for travel in the big city. However, most of the urban freeways are experiencing a severe traffic congestion caused by increased traffic. Thus, the purpose of this study is to investigate the traffic characteristics, analyze the relationships between the traffic characteristics, construct the speed-density model, and finally evaluate the capacity of the merge section within the entrance ramp junction of urban freeway in Busan city.

From the analyses of traffic characteristics, construction of the speed-density models, and evaluation of the capacity on the merge sections of urban freeway under the study, the following conclusions were drawn；

ⅰ) Flow rate showed a big difference depending on the entrance ramps on urban freeway during the weekday and weekend, and also the peak flow rate and the mixed rate of medium and large vehicles did a remarkable difference depending on the time periods.

ⅱ) Speed-density models were shown to be highly explanatory with the values greater than 0.9, and also highly correlative between speed and density with the values greater than 0.9 on the merge sections under the study.

ⅲ) Capacity showed a considerable reduction by about 30% to 39% when compared with the that of the highway capacity manual(HCM) depending on the entrance ramp merge sections of urban freeway.

ⅳ) The urban freeway traffic management system(UFTMS) measures like the changeable message sign(CMS), ramp metering system, or both were shown to be more effective on the entrance ramps in the daytime period.