9-line access access management access point accessibility ADA air quality alignment amenity antiplanner atlanta BART BID bike Blogs boston branded bus branded buses brookings brt bus Bus Rapid Transit BYU capacity car pool cars central link Centrality certification commuter rail condo conformity congestion congestion pricing connections consistency coverage crossings CRT cycling DART dedicated dedicated right of way density denver depreciation developers development dynamic pricing economics efficiency Envision Utah equity eugene exclusive extension FAQ favela Federal Funding Flex Bus florida free fare zone freeways Frequent Transit Network frontrunner frontunner Gallivan garden cities gas prices geotagging goat Google grade-separation Granary District growth headway heavy rail hedonic High Speed Rail history housing housing affordability housing bubble housing prices HOV income infill innovative intersections intensity ITS junk science LA land use LEED legacy city light rail linear park location LRT lyft M/ART malls mapping maps market urbanism metrics metro MetroRail missoula mixed mixed traffic mixed-traffic mobile mode choice Mode Share multi-family MXD neighborhood networks news NIMBY office online op-ed open letter Operations parking parking meters peak travel pedestrian environment phasing Photomorphing planning Portland property property values Provo proximity quality_transit rail railvolution rant rapid rapid transit RDA real estate redevelopment reliability research retail Ridership ridesharing right of way roadway network ROW salt lake city san diego schedule schedule span seattle separated shuttle silver line single family SLC SLC transit master plan slums smartphone snow sprawl standing stop spacing streetcar streetscape streetscaping subdivision subsidy Sugarhouse Sugarhouse Streetcar Tacoma taxi technology tenure termini time-separation TOD townhouse traffic signal tram transit transit networks transit oriented development Transit Planning transponder transportation travel time TRAX trip planning trolley tunnel uber university of utah urban design urban economics urban land UTA UTA 2 Go Trip Planner utah Utah County Utah Transit Authority vmt walking distance web welfare transit Westside Connector WFRC wheelchairs zoning

Wednesday, February 5, 2014

Reflections on Metropolitan Form and Binary Cities

Accessibility is not purely a field effect, but also a network effect. Rather than the center broadcasting a field effect, the network broadcasts a field of effect, with the strength of that field proportional to the network time-distance to the center. 
Take Binary Metropoli such as Dallas-Ft. Worth or Minneapolis-St. Paul, where two existing monocentric cities have become conjoined. The patterns of sub-centers is distinct from emergent polycentric, where monocentric cities have developed sub-centers. In monocentric cities with radial transit routes, sub-centers emerge as  function of distance from the center. As sub-centers develop sufficiently that their level of activity density warrants it, orbital routes between peripheral sub-centers will develop. For binary metropoli, the pattern is different. The intersection of radial branches between the city centers should emerge as a sub-center.

How does a sub-center differ from an 'Edge City'? Sub-centers have to do with the efficient allocation of retail and services minimize the overlap in market areas, and minimize transportation travel time to the centers.

To use the 'hierarchy of retail' as an example:

  • Regional malls...down to neighborhood,
  • Community Center/Power Center -- big box anchored, 100,000 SF 
  • Neighborhood, 55-60k SF..
  • Grocery anchored
  •  Specialty/In-line (Strip malls)
  • C-Store
The distribution is inversely proportional to their frequency. 

Edge Cities, in contrast, contain more than retail. Garreau characterized them in terms of office development. High-rise office development was traditionally the purview of downtowns, and its emergence outside them was kind of scandalous. High rise office development is associated with higher order services--not personal services and retail, but what is often called "Producer Services", or "Professional Services", characterized by FIRE industries (Finance, Industry, Real Estate).