Labels

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

Monday, August 12, 2013

Access Points for residential subdivisions

City codes typically mandate a certain width of road--typically enough for two travel lanes and on-street parking on both sides of the street. Developers like to minimize the amount of road per subdivision. Which makes sense. Grass is cheap, asphalt is expensive. They also like to minimize 'through' traffic, and so the development plats tend to have a single exit per subdivision. Which is great if you live in that particular subdivision, but hell on walkability. It's also hell on the performance of external streets--instead of some of the 'local' traffic taking places on these local streets, it all gets dumped onto high speed arterials...disrupting traffic flow, and slowing traffic. Which is problematic, as arterial streets are much much more expensive to build that local streets. And, if the traffic volumes coming out of a residential subdivision are high enough, may make it necessary to have a traffic light, at additional cost to the city, and impairment to the function of the road. Western Hills Drive, in South Jordan, is a fine example of such, with over 200 houses, and only one access point.

Adding more access points in a residential subdivision means fewer cars turning in an out of a subdivision, as use of the access is divided over more points. It also means that residents get off arterial streets faster, as they can take the more direct route to their homes, rather than needing to circle the block first. Quality city planning also mandates that developers include 'stub' streets. Streets that do not (as of yet) connect to anything, but that will connect whatever gets built in the next parcel over. Wondering if it might not be possible to go one further, and add a calculation such that there must be 1 'access point' for every 10 acres, or for every 70 units. (Or some similar ratio).