Research of Transforming the Traffic Flow in Mild Gradient Section with Freeway Auxiliary Signs

• Main Authors: LI, CHIA-LUNG, 李佳龍
• Other Authors: Woo, T. Hugh
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/14261443892022433462

碩士 === 國立交通大學 === 運輸科技與管理學系 === 101 === Mild gradient leads to the capacity reduction in some sections of the freeways, even forms a bottleneck. Setting up an auxiliary sign to recommend drivers to accelerate while passing the mild gradient is a common treatment in Taiwan for the past few years to reduce the speed drop and narrow the speed differential. This study aims to investigate whether drivers will receive the information and accelerate while passing the mild gradient to improve the capacity. The results find that after setting up auxiliary signs, the speed differential is lower in all traffic lanes. But the average speed is lower than before in overtaking lane and outside lane, leading to an average speed reduction in this experiment section. The mileage production of the overtaking lane and the outside lane are also decreased. In conclusion, the transportation ability of this section is not improved after installing the auxiliary signs. However, it should be noted that the traffic volume had increased 15% over the study period. It might cause the speed reduction and dilute the effects from these auxiliary signs.