Underground roads are operated and installed in Korea such as Shinwol-YeouI underground roads and Seobu Underground Expressway, and are expected to be continuously installed. The distance formula of the exit of the underground road presented in the 'U...
Underground roads are operated and installed in Korea such as Shinwol-YeouI underground roads and Seobu Underground Expressway, and are expected to be continuously installed. The distance formula of the exit of the underground road presented in the 'Urban Underground Road Design Guideline (2016)' is divided into two types, minimum distance, and functional distance. However, there was a limit to the part that presented the distance because it presented the distance considering only one vehicle. Also, there was an error that the distance varies depending on the location of the vehicle and the amount of rotation. Therefore, this study aims to present the appropriate distance according to the delay time generated by dividing certain scenarios and items by setting the exit part of the underground road to the front signal intersection as an analysis section.
The delay time generated according to the separation distance between the exit of the underground road and the front signal intersection was analyzed using the traffic simulation VISSIM(7.00). The guideline analyzed the parts that were not considered because they did not consider the type of exit of underground road, traffic volume, rotation ratio. The analysis results showed that the appropriate type was presented by comparing the traffic volume level, the rotation traffic ratio, and the delay time generated according to the distance according to the type of underground road exit.
Other variables include driving behavior, signal cycle, vehicle setting, and lane width. The driving behavior of the driver was different between the ground road and the underground road in order to vary the driving behavior according to the road environment. Signal cycle, vehicle setting, geometric structure, etc. were referred to Shinwol-Yeo underground road, T-GIS.Simulation divided the case to analyze various cases, and scenario execution was performed 14,000 times in total.
The results of the experiment analysis show that the difference in delay time according to the type of exit of the underground road was insufficient in the case of 4-lane road, and the difference in the number of lanes between the exit of the underground road and the ground road was found to be affected by the same conditions. The level of access traffic with delay time of less than 70seconds was analyzed to be about 1,600 to 2,400veh/hour. The higher the right-turning ratio of the variable lane type, the less delay time than the central lane type. The higher the left turn travel ratio, the higher the delay time than the variable lane type.
In the case of the one-way 6-lane, the difference in delay time according to the type of exit of the underground road was shown to occur. The number of one-way lanes was high, and it was shown that there was an effect according to the number of changes in the lane and the rotation rate. The level of access traffic with delay time of less than 70 seconds was analyzed to be about 2,400-3,600veh/hour. The higher the right-turning ratio of the variable lane type, the higher the delay time than the central lane type, and the higher the left-turning travel ratio, the lower the delay time than the variable lane type.
This study analyzed the delay time generated according to the distance between the exit type of the underground road and the front signal intersection. Due to the nature of the underground road, if you stay in the underground due to the closed environment, you will be inconvenienced to drivers due to various factors such as psychological pressure and stress.Therefore, in order to reduce the delay time generated for more than a certain time, the appropriate distance for the road environment was suggested.