| Summary: | 碩士 === 國立交通大學 === 交通運輸研究所 === 90 === Due to very limited study of the traffic flow characteristic and capacity on expressway in Taiwan , this study has used the raw data that is surveyed by IOT of MOTC to analyze the traffic & characterists to establish an appropriate set of procedures for analyzing the capacity and level of service of Hsi Pin Expressway on basic and non-basic segment .
The main contents and approaches used are as follow：
1.To determine appropriate sampling time interval of surveyed data , serving as the basis of capacity analysis of basic segment.
2.To establish the relationship between segment length and free flow speed , find out the length of basic segment not been influenced by signalized intersection .
3.To develop appropriate traffic flow models for the basic segment , which are used to evaluate the capacity and define the level of service.
4.Choosing density as the primary MOE to define level of service of basic segment , by making reference to the method of the freeway basic segment and multi-lanes highways in Taiwan and U.S.A. .
5.To establish the level of service evaluation procedures and methods that fit Hsi Pin Expressway traffic flow characteristic on non-basic segment .
The main conclusions drawn from this study are ：
1.According to the relationship between the segment length and the free flow speed , the minimum length of the basic segment is defined as 2.5 km .
2.The traffic flow models developed for the level and grade segment is that the Greenshield’s linear model is better for the level segment ; and the Underwood’s exponential model is better for the grade segment . The capacity is about 1950 pcphpl for the level segment , and about 750 pcphpl for the grade segment.
3.The critical density measured from the model is about 61 pc/km/ln for the basic segment , which is different form the freeway basic segment and the multi-lanes highways , that is mainly due to the fact that the raw free flow speed data collected by the IOT is generally too low and result in the critical density is too high .
4.Travel speed is used as the primary MOE of level of service for the non-basic segment . Procedures to predict travel speed , and to define the level of service for the non-basic segment of Hsi Pin Expressway are developed , making reference to the Urban Arterial of 2000 HCM in U.S.A. .
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