路上駐車帯の屋外飲食空間としての利用に関する研究

－フレキシブル・ゾーンとパークレットの比較を通して－

抄録

 This study focuses on “flexible zone” and Parklet as means to provide outdoor spaces for eating and drinking while utilizing parking lanes. The purpose of this study is to clarify advantages and disadvantages as well as common and different features of “flexible zone” and Parklet, and to explore ways for realizing similar spaces in Japan. A “flexible zone” is a parking lane that is allowed to convert to outdoor dining areas by adjacent business owners with government permission, and three examples, Castro Street in Mountain View, Theatre Way in Redwood City, and First Street in Livermore, exist in California in the United States. On the other hand, Parklet is the program launched in San Francisco that facilitates the installation of public pedestrian spaces on parking lanes.
 The research on “flexible zone” is based on the previous study by the author and additional field surveys. In addition, with regard to universal design that is conceived as an important aspect for the comparison with Parklet, reviews of documents regarding the operation of “flexible zones” and hearings with an urban designer in charge of the design of all three “flexible zones” have been conducted. On the other hand, with regard to Parklet, reviews of documents and previous researches regarding Parklet as well as a hearing with a city official have been conducted. In addition, field surveys of all “flexible zones” and 26 Parklets have been conducted in order to observe actual conditions and operations.
 Through the comparison between “flexible zone” and Parklet, the author clarifies common features and differences between them, and then explores 1) their uniqueness as methods of producing outdoor spaces for eating and drinking, 2) their advantages and disadvantages, and 3) ways for realizing outdoor spaces for eating and drinking on parking lanes in Japan.
 With regard to the uniqueness, both “flexible zone” and Parklet are realized through the cooperation between public and private sectors while paying lots of consideration for design, safety and comfortability. In addition, in both methods, the balance between pedestrian spaces converted from parking lanes and on-street parking spaces is considered and maintained through their permission processes as well as their spatial flexibility. On the other hand, the level of publicness is a primary difference between them, i.e. “flexible zone” is not necessarily open to the public while Parklet is required to be open to the public.
 With regard to “flexible zone”, effectiveness for the improvement of pedestrian and urban environment, possible safety measures by street design, limited cost burden on business owners, high spatial variability, and appropriate maintenance and operation by business owners are conceived as advantages, whereas substantial cost burden on the public sector and limited use by the public are conceived as a disadvantage. On the other hand, with regard to Parklet, limited cost burden on the public sector, aptitude for phasing implementation, effectiveness for the creation of interactive spaces, and feasibility at various locations and for a short period of time are conceived as advantages, whereas lack of unity of streetscape, limited spatial flexibility, heavy cost burden on business owners, and improper operation are conceived as disadvantages.
 With regard to ways for realizing in Japan, it is important to consider 1) realization methods in accordance with purposes and existing conditions of a target area, 2) responsibilities, systems and measures for securing pedestrian safety, 3) consistency with related ordinances and their necessary revisions, and 4) introduction of a phasing implementation process through pilot projects, are important in Japan.