{"id":1622,"date":"2010-06-07T21:12:59","date_gmt":"2010-06-08T01:12:59","guid":{"rendered":"http:\/\/www.alexblock.net\/?p=1622"},"modified":"2010-06-07T21:12:59","modified_gmt":"2010-06-08T01:12:59","slug":"intersection-density-centrality","status":"publish","type":"post","link":"https:\/\/www.alexblock.net\/blog\/2010\/06\/07\/intersection-density-centrality\/","title":{"rendered":"Intersection density & centrality"},"content":{"rendered":"

What is the best method to quantify what makes a place walkable?\u00a0 The Journal of the American Planning Association<\/a> recently published some powerful documentation from Robert Cervero<\/a> and Reid Ewing<\/a> on the value of pedestrian-oriented design (following up on yesterday’s links<\/a>).\u00a0 Grist has the article<\/a> (hat tip to Planetizen<\/a>), citing Laurence Aurbach’s PedShed blog<\/a> – again, the “Three D’s<\/a>” or urbanism emerge front and center – density, diversity, and design:<\/p>\n

Their findings? Of all the built environment measurements, intersection density has the largest effect on walking \u2014 more than population density, distance to a store, distance to a transit stop, or jobs within one mile. Intersection density also has large effects on transit use and the amount of driving. The authors comment,<\/p>\n

This is surprising, given the emphasis in the qualitative literature on density and diversity, and the relatively limited attention paid to design.<\/p><\/blockquote>\n<\/blockquote>\n

In other words, intersection density is the most important factor for walking and one of the most important factors for increasing transit use and reducing miles driven, but gets relatively little attention in research and in public policy.<\/p><\/blockquote>\n

In other words, the other two D’s (density and diversity) get more play than design.\u00a0 Perhaps that’s because density and diversity (of land use, of people, of incomes, etc) were easier to quantify than something as seemingly subjective as design.<\/p>\n

\"Intersection_Density\"<\/a><\/p>\n

Kaid Benfield ties these principles<\/a> to those angry about the ever expanding oil slick<\/a> in the Gulf of Mexico, hitting on another theme of the research – location:<\/p>\n

The study’s\u00a0key conclusion is that destination accessibility is by far the most important land use\u00a0factor in determining a household or person\u2019s amount of driving.\u00a0 To explain, ‘destination accessibility’ is a technical term that describes a given location\u2019s\u00a0distance\u00a0from common trip destinations (and origins).\u00a0 It almost always favors central locations within a region; the closer a house, neighborhood or office is to downtown, the better its accessibility and the lower its rate of driving.\u00a0 The authors found that such locations can be almost as significant in reducing driving rates as other significant factors (e.g.<\/em>, neighborhood density, mixed land use, street design) combined<\/em>.<\/p>\n

The clear implication is that, to enable lifestyles with reduced driving, oil consumption\u00a0and associated emissions, environmentalists should continue to stress opportunities for revitalization and redevelopment in centrally located neighborhoods.\u00a0 As Ewing and Cervero put it:\u00a0\u00a0‘Almost any development in a central location is likely to generate less automobile travel than the best-designed, compact, mixed-use development in a remote location.’<\/strong><\/p><\/blockquote>\n

Aurbach is quick to note the limitations of the study, but even with those this is an exciting quantification and potential metric for walkable and sustainable design.\u00a0 It builds off the Jacobs legacy of ‘short blocks’<\/a> and adds some science behind recent GGW posts from Erik Bootsma<\/a> and Daniel Narin<\/a> on the variety and histories of street grids.\u00a0 This kind of research lends weight to the anecdotal accounts of Portland’s small blocks resulting from the belief that corner lots were more valuable<\/a>, as well as ideas of better utilization of alley space – such as this recent post<\/a> from Richard Layman.<\/p>\n","protected":false},"excerpt":{"rendered":"

What is the best method to quantify what makes a place walkable?\u00a0 The Journal of the American Planning Association recently published some powerful documentation from Robert Cervero and Reid Ewing on the value of pedestrian-oriented design (following up on yesterday’s links).\u00a0 Grist has the article (hat tip to Planetizen), citing Laurence Aurbach’s PedShed blog – […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","enabled":false},"version":2}},"categories":[89],"tags":[138,222,451,481,137,221,209,220],"class_list":["post-1622","post","type-post","status-publish","format-standard","hentry","category-planning","tag-3ds","tag-centrality","tag-density","tag-design","tag-diversity","tag-intersection-density","tag-oil-spill","tag-walkability"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/pHcGQ-qa","jetpack_sharing_enabled":true,"jetpack-related-posts":[],"_links":{"self":[{"href":"https:\/\/www.alexblock.net\/blog\/wp-json\/wp\/v2\/posts\/1622","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.alexblock.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.alexblock.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.alexblock.net\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.alexblock.net\/blog\/wp-json\/wp\/v2\/comments?post=1622"}],"version-history":[{"count":10,"href":"https:\/\/www.alexblock.net\/blog\/wp-json\/wp\/v2\/posts\/1622\/revisions"}],"predecessor-version":[{"id":1633,"href":"https:\/\/www.alexblock.net\/blog\/wp-json\/wp\/v2\/posts\/1622\/revisions\/1633"}],"wp:attachment":[{"href":"https:\/\/www.alexblock.net\/blog\/wp-json\/wp\/v2\/media?parent=1622"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.alexblock.net\/blog\/wp-json\/wp\/v2\/categories?post=1622"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.alexblock.net\/blog\/wp-json\/wp\/v2\/tags?post=1622"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}