都市道路組成與行人熱舒適關係之研究

Abstract

臺灣自1999年起推行「人本交通」的概念，期望能在都市中提供舒適的步行環境。但經過重新規劃設計後的道路是否真的能成為一個舒適的人本交通環境，則少有相關的研究討論。本研究的目的為探討不同的道路組成對行人的人體熱舒適之影響，量化不同道路組成下的行人熱舒適度，以供未來道路規劃設計之參考。 道路的微氣候會受到道路組成因子的影響，如道路走向、道路高寬比、車道數量、植栽綠帶數量、植栽種類等。本研究調查了臺北市區內所有40公尺的主要道路並歸納成10種道路組成類型做為方案發展參考，使用ENVI-met微氣候模擬軟體為研究工具，並選擇道路組成類型為類型一的一個路段為實測地點進行實測，驗證氣溫、平均輻射溫度、生理等效溫度等資料。經驗證確定為可信任的模型後，以驗證地點的模型修正後做為基礎方案模型，搭配不同道路走向、綠帶數量及植栽種類組合成12種道路組成方案，計算不同方案之熱舒適度。 研究結果發現道路走向、道路植栽綠帶數量、植栽種類皆會影響行人的熱舒適。其中道路走向對熱舒適的影響最大，在所有的道路類型中，南-北走向的道路皆比東-西走向的道路舒適。而在同樣走向的道路中，植栽綠帶道路組成也會影響熱舒適度。植栽綠帶數量越多的類型可提供較多遮蔭，其生理等效溫度（PET）比植栽綠帶較少的類型低。此外，植栽種類也會影響行人熱舒適，葉面積指數（LAI）較高的植栽可阻擋較多輻射，因此在相同走向及相同綠帶數量的情況下會比使用低LAI的植栽者舒適。

The concept of Humanity-Oriented Transportation had been applied in road design and construction in Taipei city since 1999. By manipulating the composition of a road, an accessible, wider, and more vegetation sidewalk can be created. Since then, some roads were remodeled to provide a more comfortable and preferable walking experience for pedestrians. However, there are a few studies assessing the benefits of the Humanity-Oriented Transportation design. The purpose of this study was to investigate the effect of road composition on pedestrian thermal comfort. According to previous studies, the microclimate of a road was influenced by road compositions such as road orientation, aspect ratio, number of lanes, number of planting strips and tree species. This study surveyed all 40 m wide roads in Taipei city and concluded 10 types of road compositions. The ENVI-met microclimate simulation software was used to calculate PET for each scenario. The verification was done by comparing the measurement values with simulated values, including air temperature, mean radiant temperature, and PET. The site model we chose to validate was further varied by varying road orientation, greenbelts and LAI of trees to create 12 road composition scenarios. The study results showed that road orientation had a significant effect on the thermal comfort of a road. Among the 12 scenarios, the thermal comfort of N-S roads was much more comfortable than E-W roads. Road type with greater vegetation performed a better thermal comfort than other road composition types, while road orientation was fixed. In addition, roads planted with high LAI trees revealed a better thermal comfort than roads planted with low LAI trees.