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利用者:加藤勝憲/歩きやすさ or ウォーカビリティ

De la Gauchetière Street, Montreal
Chinatown, New York City

ウォーカビリティ（Walkability）とは、高密度の近隣にアメニティが混在し、人々がそのアメニティに徒歩でアクセスできるような計画コンセプトのことである[1]。この考え方は、都市空間は、自動車が最大限の処理能力を発揮できるように設計された単なる輸送通路であってはならないという考えに基づいている。その代わりに、多様な用途、利用者、交通手段に対応し、移動のための自動車の必要性を減らす、比較的完全な住みやすい空間であるべきだ。

歩きやすさ（walkability）」という用語は、主に1960年代にジェイン・ジェイコブズによる都市研究の革命に よって考案された。近年、ウォーカビリティは、その健康、経済、環境面での利点から普及している[2]。持続可能な都市デザインに不可欠な概念である[3]。ウォーカビリティに影響を与える要因としては、歩道、歩道、その他の歩行者専用道路の有無や質、交通や道路の状況、土地利用のパターン、建物へのアクセス、安全性などが挙げられる。

include the presence or absence and quality of footpaths, sidewalks or other pedestrian rights-of-way, traffic and road conditions, land use patterns, building accessibility, and safety, among others.

要因[編集]

Mixed use pedestrian friendly street in Bitola, North Macedonia.

ウォーカビリティの定義として、次のようなものが提案されている： 「ある地域に住む人、買い物をする人、訪れる人、楽しむ人、 時間を過ごす人の存在に対して、建築環境がどの程度フレンドリー であるかということである」。ウォーカビリティは、密度、ミックス、アク セスの相互依存の相乗効果に依存している。都市のDMA（密度、ミックス、アクセス）とは、都市が人や建物を集中させる方法、異なる人々や活動をどのようにミックスさせるか、そしてその中を移動するために利用されるアクセスネットワークの間の相乗効果の集合である[1]。

これらの要素を単独で捉えることはできない。理想的な機能的ミックスではなく、フォーマル、社会的、機能的ミックスのミックスと相互依存が存在する。同様に、歩行可能なアクセスは、接続性、浸透性、集散性といった単一の指標に還元することはできないが、目的地に依存し、公共交通機関のノードを介した大都市アクセスに連動している。DMAは歩きやすさの指標に基づいているが、人気のある「ウォークスコアwalk score’」や「ミストリート評価walk score」のウェブサイトは、都市の形態をより良い環境と健康の結果に結びつけるための、より多くの指標を提供している。

Density[編集]

密度とは、建物、人口、街路生活の相互に関連した集合体である。密度は、徒歩で移動可能な距離により多くの人や場所が集中するため、歩きやすさの重要な特性である。郊外から都心部まで人口が変動するため、密度を決定することは困難である[1]。さらに、密度の尺度は、形態や建物の類型によって大きく異なることがある。密度は建物の高さと混同されることがあり、混乱の一因となっている。床面積と敷地面積の比は、一般に容積率（Floor Area Ratio、FAR、容積指数とも呼ばれる）として知られている。例えば、敷地の10％に10階建ての建物を建てた場合、敷地面積100％の平屋建ての建物と同じ床面積になる[1]。

第二に、住居数／ヘクタールという指標は一般的だが、特に鈍感である。これは、機能的ミックス、世帯数、そして建物密度や人口密度との関係における住居の大きさに依存する。より大きな住宅は、同じ人口に対してより高い建築密度をもたらし、より大きな世帯は、同じ住宅数に対してより高い人口をもたらす。機能的に混在した近隣地域では、住宅は混在の一要素に過ぎず、したがって建物密度や人口密度の尺度にはならない。国勢調査に基づく居住者密度/ヘクタールも一般的な指標であるが、これにはそこで働く人は含まれない。

Functional mix[編集]

Functional mix, like density, shortens the distances between wherever we are and where we need to be. The live/work/visit triangle constructs a field of possible relations between three primary functions that resonate with what economists have often called reproduction, production, and exchange (incorporating social exchange).[2] They also identify primary relations between people and urban space – we become ‘residents,’ ‘workers,’ and ‘visitors,’ respectively, in different locations in everyday life. The key shift here lies in focusing on the mix rather than their functions. Such mapping offers an empirical understanding of the mix that enables us to expose different kinds and levels of a mix. It is tempting to construct an index for an ideal mix measured by the degree of lightness as the mix approaches the center of the triangle. However, we suggest that the best cities comprise a mix of mixes. Our attention should focus instead on the corners of the triangle – the dysfunctional parts of cities where one can- not walk between living, work, and visiting functions.

While the functional mix is crucial to any approach to walkability, it is important to note here that function is itself but one dimension of the urban mix, including the formal and social mix. A formal mix emerges from how a city produces different plot sizes, which are linked to different building styles, floor plate sizes, and building heights.[1] While a small-grain urban fabric is linked to a more mixed neighborhood, large grains also need because some functions rely on those large grains to become part of the mix. The social mix has to do with how a good city brings together people of different ages, abilities, ethnicities, and social classes. Cities are places where differences rub together in walkable public spaces, and this mix of differences is fundamental to the production of urban vitality. Again, there is no single index for mix in its impact on walkability. The concept is fundamentally relational, both between functions and the formal and social mix sustaining them.

Access networks[編集]

Cover of The Death and Life of Great American Cities

The access networks of a city enable and constrain pedestrian flows; it is the capacity or possibility to walk. Like density and mix, these are properties embodied in urban form and facilitate more efficient pedestrian flows. Access networks are also multi-modal and need to be understood from the perspective of those who choose between modes of walking, cycling, public transport, and cars. Public transport trips are generally coupled with walkable access to the transit stop. Walking will primarily be chosen for up to 10 minutes if it is the fastest mode and other factors are equal. Walking has the advantage that it is a much more predictable trip time than public transport or cars, where we have to allow for delays caused by poor service, congestion, and parking.[4] Major infrastructural factors include access to mass transit, presence and quality of footpaths, buffers to moving traffic (planter strips, on-street parking or bike lanes) and pedestrian crossings, aesthetics, nearby local destinations, air quality, shade or sun in appropriate seasons, street furniture, traffic volume and speed.[5] and wind conditions. Walkability is also examined based on the surrounding built environment. Reid Ewing and Robert Cervero's five D's of the built environment—density, diversity, design, destination accessibility, and distance to transit—heavily influence an area's walkability. Combinations of these factors influence an individual's decision to walk.

History[編集]

Before cars and bicycles were mass-produced, walking was the main way to travel. It was the only way to get from place to place for much of human history.[6] In the 1930s, economic growth led to increased automobile manufacturing. Cars were also becoming more affordable, leading to the rise of the automobile during the Post–World War II economic expansion. The detrimental effects of automobile emissions soon led to public concern over pollution. Alternatives, including improved public transportation and walking infrastructure, have attracted more attention from planners and policymakers. There is a correlation between the white exodus from racially mixed urban regions to more racially homogeneous suburban regions with the growth of an automobile centric urban planning. Jane Jacobs The Death and Life of Great American Cities remains one of the most influential books in the history of American city planning especially concerning the future developments of the walkability concept. She coined the terms "social capital", "mixed primary uses", and "eyes on the street", which were adopted professionally in urban design, sociology, and many other fields. While there has been a push towards better walkability in cities in recent years, there are still many obstacles that need to be cleared to achieve more complete and cohesive communties where residents won't have to travel as far to get to where they need to go. For example, the average time it has taken American commuters to get to work has actually increased from 25 to 27.6 minutes, so much is still to be done if walkability is to be realized and a lessened reliance on cars comes into fruition.

Benefits[編集]

Health[編集]

 

Walkability indices have been found to correlate with both Body Mass Index (BMI) and physical activity of local populations.[7][8] Physical activity can prevent chronic diseases, such as cardiovascular disease, diabetes, hypertension, obesity, depression, and osteoporosis. Thus for instance, an increase in neighborhood Walk Score has linked with both better Cardio metabolic risk profiles[9] and a decreased risk of heart-attacks.[10] The World Cancer Research Fund and American Institute for Cancer Research released a report that new developments should be designed to encourage walking, on the grounds that walking contributes to a reduction of cancer. A further justification for walkability is founded upon evolutionary and philosophical grounds, contending that gait is important to the cerebral development in humans.

Due to discrepancies between residents' health in inner city neighborhoods and suburban neighborhoods with similar walkability measures, further research is needed to find additional built environment factors in walkability indices.[11]

Walking bus in Třebíč, Czech Republic

Socioeconomic[編集]

Walkability has also been found to have many socioeconomic benefits, including accessibility, cost savings both to individuals and to the public, student transport (which can include walking buses), increased efficiency of land use, increased livability, economic benefits from improved public health, and economic development, among others.[12] The benefits of walkability are best guaranteed if the entire system of public corridors is walkable - not limited to certain specialized routes. More sidewalks and increased walkability can promote tourism and increase property value.[13]

In recent years, the demand for housing in a walkable urban context has increased. The term "Missing Middle Housing" as coined by Daniel Parolek of Opticos Design, Inc.,[14] refers to multi-unit housing types (such as duplexes, fourplexes, bungalow courts, and mansion apartments not bigger than a large house), which are integrated throughout most walkable Pre-1940s neighborhoods, but became much less common after World War II, hence the term "missing." These housing types are often integrated into blocks with primarily single-family homes, to provide diverse housing choices and generate enough density to support transit and locally-serving commercial amenities.

Auto-focused street design diminishes walking and needed "eyes on the street" provided by the steady presence of people in an area. Walkability increases social interaction, mixing of populations, the average number of friends and associates where people live, reduced crime (with more people walking and watching over neighborhoods, open space and main streets), increased sense of pride, and increased volunteerism.

Socioeconomic factors contribute to willingness to choose walking over driving. Income, age, race, ethnicity, education, household status, and having children in a household all influence walking travel.

Environmental[編集]

One of benefits of improving walkability is the decrease of the automobile footprint in the community. Carbon emissions can be reduced if more people choose to walk rather than drive or use public transportation, so proponents of walkable cities describe improving walkability as an important tool for adapting cities to climate change. The benefits of less emissions include improved health conditions and quality of life, less smog, and less of a contribution to global climate change.[15] Further, cities that developed under guiding philosophies like walkability typically see lower levels of noise pollution in their neighborhoods. This goes beyond just making quieter communities to live, less noise pollution can also mean greater biodiversity. Studies have shown that noise pollution can disrupt certain senses that animals rely on to find food, reproduce, avoid predators, etc. which can weaken ecosystems in an already human dominated environment. [16] [17] Society depends on these ecosystem for many ecological services such as provisioning, regulation, cultural/tourism, and supporting services [18] and any degradation of these services can go beyond just affecting the aesthetic of a neighborhood or community but can have serious implications for livability and wellbeing on entire regions.

Cities that have a relatively walkability score also tend to have a higher concentration of green spaces which facilitate a more walkable city. These green spaces can assist in regulatory ecological services such as flooding, improving the quality of both air and water, carbon sequestration, etc. all while also improving the attractiveness of the city or town in which it's implemented in.[19]

Increasing walkability[編集]

A brick-paved sidewalk in Hudson, Ohio

Many communities have embraced pedestrian mobility as an alternative to older building practices that favor automobiles. This shift includes a belief that dependency on cars is ecologically unsustainable. Automobile-oriented environments engender dangerous conditions for motorists and pedestrians and are generally bereft of aesthetics.[20] A type of zoning called Form-based coding is a tool that some American cities, like Cincinnati, are employing to improve walkability.[21][22] The COVID-19 pandemic gave birth to proposals for radical change in the organization of the town, in particular Barcelona, being the elimination of the car and consequent pedestrianization of the whole city one of the critical elements, and proposing an inversion of the concept of the sidewalk.[23][24][25]

There are several ways to make a community more walkable:

  • Buffers: Vegetation buffers as grass areas between the street and the sidewalk also make sidewalks safer and also absorbs the carbon dioxide from automobile emissions and assists with water drainage.
  • Moving obstructions: removing signposts and utility poles, can increase the walkable width of the sidewalk. Quality maintenance and proper sidewalks lighting reduce obstructions, improve safety, and encourage walking.
  • Sidewalk gaps: Sidewalks can be implemented where there are "sidewalk gaps," with priority to areas where walking is encouraged, such as around schools or transit stations. Campaigns such as Atlanta, Georgia's safe transit routes provide safer access to transit stops for pedestrians. There are several aspects to consider when implementing new sidewalks, such as sidewalk width. The Americans with Disabilities Act (ADA) requires that sidewalks be at least five feet in width.
  • Pedestrian zone: New infrastructure and pedestrian zones replace roads for better walkability. Cities undertake pedestrian projects for better traffic flow by closing automobile access and only allowing pedestrians to travel. Projects such as the High Line and the 606 Trail increase walkability by connecting neighborhoods, using landscape architectural elements to create visually aesthetic green space and allowing for physical activity. Towns can also be modified to be pedestrian villages.
  • Curb extensions: Curb extensions decrease the radii of the corners of the curb at intersections, calm traffic, and reduce the distance pedestrians have to cross. On streets with parking, curb extensions allow pedestrians to see oncoming traffic better where they otherwise would be forced to walk into the street to see past parked cars. Striped crosswalks, or zebra crossings, also provide safer crossings because they provide better visibility for both drivers and pedestrians.Improving crosswalk safety also increases walkability.
  • Improving safety: Monitoring and improving safety in neighborhoods can make walking a more attractive option. Safety is the primary concern among children when choosing how to get to and from school. Ensuring safer walking areas by keeping paths well-maintained and well-lit can encourage walkability.
  • Work from home: working from home completely eliminates any travel time associated with work and allows for people to use the time spent commuting, an average of 27.6 minutes in America. An increase in people working from home in recent years after the COVID 19 pandemic not only has cut down on fossil fuels burned, but also has other benefits like improving productivity.[26]

Measuring[編集]

One way of assessing and measuring walkability is to undertake a walking audit. An established and widely used walking audit tool is PERS (Pedestrian Environment Review System) which has been used extensively in the UK.

A simple way to determine the walkability of a block, corridor or neighborhood is to count the number of people walking, lingering and engaging in optional activities within a space. This process is a vast improvement upon pedestrian level of service (LOS) indicators, recommended within the Highway Capacity Manual. However it may not translate well to non-Western locations where the idea of "optional" activities may be different. In any case, the diversity of people, and especially the presence of children, seniors and people with disabilities, denotes the quality, completeness and health of a walkable space.[27]

A number of commercial walkability scores also exist:

  • Walk Score is a walkability index based on the distance to amenities such as grocery stores, schools, parks, libraries, restaurants, and coffee shops. Walk Score's algorithm awards maximum points to amenities within 5 minutes' walk (.25 mi), and a decay function assigns points for amenities up to 30 minutes away. Scores are normalized from 0 to 100.
  • Walkonomics was a web app that combines open data and crowdsourcing to rate and review the walkability of each street. As of 2011, Walkonomics claimed to have ratings for every street in England (over 600,000 streets) and New York City., although it stopped service in 2018.
  • RateMyStreet is a website that uses crowdsourcing, Google Maps and a five star rating system to allow users to rate the walkability of their local streets. Users can rate a street using eight different categories: Crossing the street, pavement/sidewalk width, trip hazards, wayfinding, safety from crime, road safety, cleanliness/attractiveness, and disabled peoples' access.

Mapping[編集]

A newly developing concept is the transit time map (sometimes called a transit shed map), which is a type of isochrone map.[28] These are maps (often online and interactive) that display the areas of a metropolis which can be reached from a given starting point, in a given amount of travel time. Such maps are useful for evaluating how well-connected a given address is to other possible urban destinations, or conversely, how large a territory can quickly get to a given address. The calculation of transit time maps is computationally intensive, and considerable work is being done on more efficient algorithms for quickly producing such maps. To be useful, the production of a transit time map must take into consideration detailed transit schedules, service frequency, time of day, and day of week.[29][30][31][32][33] Moreover, the recent development of computer vision and street view imagery has provided significant potential to automatically assess spaces for pedestrians from the ground level.[34]

政策[編集]

=== 日本 ===

参照[編集]

Template:Walking

脚注[編集]

Template:Transportation-planning

Further reading[編集]

外部リンク[編集]

[[Category:持続可能な交通]] [[Category:未査読の翻訳があるページ]]

  1. ^ a b c d e Dovey, Kim; Pafka, Elek (January 2020). “What is walkability? The urban DMA” (英語). Urban Studies 57 (1): 93–108. doi:10.1177/0042098018819727. ISSN 0042-0980. http://journals.sagepub.com/doi/10.1177/0042098018819727. 
  2. ^ a b “Walkability Is Good for You”, Bloomberg.com, (11 December 2014), https://www.citylab.com/design/2014/12/growing-evidence-shows-walkability-is-good-for-you-and-for-cities/383612/ 
  3. ^ “S. Grignaffini, S. Cappellanti, A. Cefalo, "Visualizing sustainability in urban conditions", WIT Transactions on Ecology and the Environment, Vol. 1, pp. 253-262, 10 Jun 2008.”. 2012年2月23日時点のオリジナルよりアーカイブ。2009年2月26日閲覧。
  4. ^ Robertson, Margaret (2014). Sustainability Principles and Practice. Routledge. pp. ppl: 208–222. ISBN 9780203768747 
  5. ^ Ramirez (2006年12月). “Indicators of Activity-Friendly Communities: An Evidence-Based Consensus Process”. American Journal of Preventive Medicine. pp. 515–24. etal時点におけるアーカイブ。. エラー: |archivedate=を指定した場合、|archiveurl=の指定が必要です。. http://www.ajpm-online.net/article/PIIS0749379706003059/fulltext 
  6. ^ Rich (2015年4月23日). “The History of a City Underfoot”. The New York Times Magazine. The New York Times Company. 2015年11月22日閲覧。
  7. ^ Frank (Winter 2006). “Many Pathways from Land Use to Health”. Journal of the American Planning Association. p. 77. etal時点におけるアーカイブ。. エラー: |archivedate=を指定した場合、|archiveurl=の指定が必要です。. http://www.planning.org/japa/pdf/JAPAFrank06.pdf 
  8. ^ Frank (2005年2月). “Linking objectively measured physical activity with objectively measured urban form: Findings from SMARTRAQ”. American Journal of Preventive Medicine. pp. 117–25. etal時点におけるアーカイブ。. エラー: |archivedate=を指定した場合、|archiveurl=の指定が必要です。. http://www.ajpm-online.net/article/PIIS0749379704003253/fulltext 
  9. ^ Méline, Julie; Chaix, Basile; Pannier, Bruno; Ogedegbe, Gbenga; Trasande, Leonardo; Athens, Jessica; Duncan, Dustin T. (2017-12-19). “Neighborhood walk score and selected Cardiometabolic factors in the French RECORD cohort study”. BMC Public Health 17 (1): 960. doi:10.1186/s12889-017-4962-8. ISSN 1471-2458. PMC 5735827. PMID 29258476. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5735827/. 
  10. ^ Mazumdar, Soumya; Learnihan, Vincent; Cochrane, Thomas; Phung, Hai; O'Connor, Bridget; Davey, Rachel (2016-12-01). “Is Walk Score associated with hospital admissions from chronic diseases? Evidence from a cross-sectional study in a high socioeconomic status Australian city-state” (英語). BMJ Open 6 (12): e012548. doi:10.1136/bmjopen-2016-012548. ISSN 2044-6055. PMC 5168632. PMID 27932340. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5168632/. 
  11. ^ Lopez, Russel P. and H. Patricia Hynes. “Obesity, physical activity, and the urban environment: public health research needs”. Environmental Health (Environmental Health: A Global Access Science Source) 5. doi:10.1186/1476-069X-5-25. http://www.ehjournal.net/content/5/1/25 
  12. ^ Todd Littman, "Economic Value of Walkability", Transportation Research Board of the National Academies, Vol. 1828, 2003., Litman, Todd Alexander (2004年10月12日). “Economic Value of Walkability”. Victoria Transport Policy Institute. http://www.vtpi.org/walkability.pdf 
  13. ^ “Planning for Complete Communities in Delaware”. Template:Cite webの呼び出しエラー：引数 accessdate は必須です。
  14. ^ Parolek. “Missing Middle Housing: Responding to the Demand for Walkable Urban Living”. Opticos Design, Inc.. 2012年4月6日閲覧。
  15. ^ “Walkable Cities @ProjectDrawdown #ClimateSolutions” (英語). Project Drawdown (2020年2月6日). 2020年11月27日閲覧。
  16. ^ “How the built environment influences walking and cycling”, Promoting walking and cycling (Bristol University Press): 67–84, doi:10.2307/j.ctt1t6p71q.11, http://dx.doi.org/10.2307/j.ctt1t6p71q.11 2022年5月30日閲覧。 
  17. ^ “How does walking and cycling help to protect the environment?” (英語). Sustrans. 2022年5月30日閲覧。
  18. ^ “Ecosystem Services” (英語). National Wildlife Federation. 2022年5月30日閲覧。
  19. ^ Cartier (2021年5月21日). “Growing Equity in City Green Space” (英語). Eos. 2022年5月30日閲覧。
  20. ^ Zehner, Ozzie (2012). Green Illusions. Lincoln and London: University of Nebraska Press. pp. 263–300. http://www.greenillusions.org/ 
  21. ^ Yung. “Here's how Cincinnati's form-based codes are designed to spur redevelopment”. 2018年4月16日閲覧。
  22. ^ “Cincinnati Form-Based Code”. Form-Based Codes Institute. Template:Cite webの呼び出しエラー：引数 accessdate は必須です。
  23. ^ Maiztegui, Belén (2020年6月18日). “Manifiesto por la reorganización de la ciudad tras el COVID-19” (スペイン語). https://elpais.com/elpais/2020/05/06/alterconsumismo/1588769208_267470.html 2021年5月11日閲覧。 
  24. ^ Argemí, Anna (2020年5月8日). “Por una Barcelona menos mercantilizada y más humana” (スペイン語). https://elpais.com/elpais/2020/05/06/alterconsumismo/1588769208_267470.html 2021年5月11日閲覧。 
  25. ^ Paolini, Massimo (2020年4月20日). “Manifesto for the Reorganisation of the City after COVID19” (英語). https://www.degrowth.info/en/2020/05/manifesto-for-the-reorganisation-of-the-city-after-covid-19/ 2021年5月1日閲覧。 
  26. ^ Parker (2022年2月16日). “COVID-19 Pandemic Continues To Reshape Work in America” (英語). Pew Research Center’s Social & Demographic Trends Project. 2022年5月30日閲覧。
  27. ^ Zehner, Ozzie (2012). Green Illusions. Lincoln and London: University of Nebraska Press. pp. 250–51, 265–66. http://www.greenillusions.org/ 
  28. ^ Dovey, K., Woodcock, I. & Pike, L. (2017) 'Isochrone Mapping of Urban Transport', Planning Practice & Research, 32(4): 402-416. doi:10.1080/02697459.2017.1329487
  29. ^ “Transit Time Map: Bay Area, 9:00am”. Walk Score. Walk Score. 2013年2月25日閲覧。
  30. ^ Wehrmeyer. “Dynamic Public Transport Travel Time Maps”. Mapnificent. Stefan Wehrmeyer. 2013年2月25日閲覧。
  31. ^ Roth (2009年3月12日). “Walk Score Updates Transit Travel Map for Bay Area”. sf.streetsblog.org. streetsblog.org. 2013年2月25日閲覧。
  32. ^ Walker (2011年1月24日). “Beyond "transit scores": an exchange with Matt Lerner”. Human Transit. humantransit.org. 2013年2月25日閲覧。
  33. ^ Wehrmeyer (2010年10月31日). “A Mapnificent World”. On the Things I Do. stefanwehrmeyer.com. 2013年2月25日閲覧。
  34. ^ Ito, K.; Biljecki, F. (2021). “Assessing bikeability with street view imagery and computer vision”. Transportation Research Part C: Emerging Technologies 132: 103371. arXiv:2105.08499. doi:10.1016/j.trc.2021.103371. 
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