| Summary: | 碩士 === 逢甲大學 === 環境工程與科學所 === 97 === This study is to evaluate the change of traffic-patterns and air quality due to the construction of the NO.6 freeway. A in-situ vehicle counting program were performed while the coincident counting data from the toll station were collected. Then CALINE 4 model was utilized to simulate the air pollution on both weekday and weekend in Nantou County. Finally, the effects of air quality of the main traffic line regions and population concentrated regions, such as Guoshing and Puli were evaluated.
The result show that, the Total Traffic Index (TTI) value of the traffic in and out of Nantou County for weekday and weekend were 1.075 and 1.571, respectively. It was indicated that the NO.6 freeway did attract a large number of vehicles, especially on weekend. Vacation Traffic Index (VTI) value before and after the construction of NO.6 freeway were 1.463 and after 2.136, respectively. As it was seen, all VTI values were larger than 1, showed that there were more vehicles on weekend than those on weekday. And the VTI value after construction of NO.6 freeway was much larger than those before construction.
On the other hand, the TTI value of the 14th provincial highway (parallel to the NO.6 freeway) on weekday and weekend were 0.730 and 0.773, respectively. It revealed that the TTI values were all smaller than 1, meant that the traffic of the 14th provincial highway was reduced owing to the construction of NO.6 freeway. VTI values of the 14th provincial highway before and after the construction of NO.6 freeway were 1.210 and 1.281, respectively, it revealed only a small increment in weekend after construction. But if the 14th provincial highway and NO.6 freeway were considered altogether, the VTI values before and after the construction of NO.6 freeway were 1.210 and 1.634, respectively. It revealed that a large amount of increment of weekend traffic were observed after the construction of NO.6 freeway.
According to the numerical simulation, the highest concentration was found near Formosan Freeway, Tsautun interchange, before the construction of NO.6 freeway. It was found changing to near Jhushan town and Nantou city. For air pollutant CO, the Air Pollution Assessment Index (APAI) value was less than 1 on both weekday and weekend, at all evaluating regions: the N-S traffic line region, Guoshing and Puli regions. It revealed that after construction of NO.6 freeway, the air quality CO was better at all these regions. For air pollutant SO2, the APAI value was larger than 1 on weekday at all regions. It revealed that air quality SO2 were worse at these regions. However, the APAI values were smaller than 1 on weekend. It revealed that after construction of NO.6 freeway, air quality SO2 was better due to part of the overcrowded traffic on the 14th provincial highway has been transferred to NO.6 freeway.
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