Design Criteria of the Mixed Lane Width on Urban Arterial

• Main Authors: Fu-Jen Yang, 楊孚仁
• Other Authors: Tien-Pen Hsu
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/99466125018411004939

碩士 === 國立臺灣大學 === 土木工程學研究所 === 95 === Lane width is one of the factors composed of the cross section, it also can regulate the right of way of vehicles, and it affects on driving safety and efficiency significantly. In the past, there is less investigations focus on lane width in Taiwan. For this reason, the subject is focus on mixed lane width to analyze the effects on safety and efficiency of mixed traffic with different mixed lane widths and to draft design criteria of the mixed lane width on urban area for the purpose of engineering application. Data were collected at five sections of urban arterials in Taipei city, the widths were 3.0, 3.5, 4.0, 4.5 and 5.0 m respectively. The condition of traffic flow was recorded by Digital Vedio survey on the top of buildings, and some parameters of traffic flow can be gotten like traffic flow, average running speed, average degree of disorder, traffic composition…etc. In the next step, using fundamental diagram, statistics test, and speed distribution chart can treat about the traffic flow condition, the difference of average running speed, and average degree of disorder under differential mixed lane widths. The results of analysis shown that 3.5 and 4.0 m had both better condition for average running speed and average degree of disorder. After drawing the flow-degree of disorder chart, the special relationship between flow and degree of disorder can be shown that “As increase of traffic flow, the degree of disorder would be compressed into a stable value gradually”. The two-stage artificial neuron networks would be as methodology for drafting design criteria originally. However, after the process of trial and error, the model performance was always not good. Finally, we found that the characteristic of surface type distribution of mixed traffic flow should be the main reason. Therefore, taking advantage of the special relationship between flow and degree of disorder to set a mathematical pattern for substituting the artificial neuron network, and apply this mathematical pattern for drawing up the design criteria, the results are followed as： 1. When traffic volume of mixed lane is under 4000 veh/hr (or 1500 pcu/hr), mixed lane width should be designed as 3.5 meter. 2. When traffic volume of mixed lane is over 4000 veh/hr (or 1500 pcu/hr), mixed lane width should be designed as 4.0 meter.