72 Economic dimensions and socio-cultural patterns
Third, communities that have been bisected by a highway commonly have
both reduced social interactions and greater environmental justice issues (Jacobs
1992). Creating walkways and bikeways under or over the bisecting highway can
help mitigate the degradation and reestablish a sense of community. However,
designing the structures to be well vegetated and wide for good lateral vision also
facilitates crossing by wildlife, thus revitalizing surrounding animal populations
and nature.
Afourth approach,transit-oriented development(TOD), refers to urbanization
centered around nodes with public transportation (Cervero1993, 1998,Calthorpe
1993,Dittmar and Ohland2004). Such development is typically moderate- to
high-density mixed-use within an easy walk of a major transit stop. Mixed-use
especially refers to residential and shopping areas in proximity, though industry
and employment may also be included. Planners usually use 800 m (1/2 mile) as
theradius for TOD. However, an easy walk also means a network of attractive
safe paths or sidewalks, particularly radiating outward from the transit node
(Handy1992, 2005).
Transit-oriented development should reduce vehicular travel somewhat and
also enhance walking and shopping close to home. Those in turn should trans-
late into greater social interactions and sense of community, compared with a
sprawl area. Also, if a sense-of-place results from relating to and caring about
thecombination of nature and human structures somewhere, then generating
asense of place for people will doubtless depend on a serious protection of, and
provision for, natural areas in a TOD nodal area.
The San Diego trolley, Los Angeles commuter rail, and Portland (Oregon) light
rail systems all have transit-oriented development around some stations along
radial commuter routes (Cervero1993,Ozawa2004;Hollie M. Lund, 2006 website,
http://www.csupomona.edu/-rwwillson/tod). In California, TOD residents have higher
ratesoftransit use than people in adjacent areas, the city as a whole, and other
cities and regions. Residents are about five times as likely to commute by transit
as workers across the city. Transit-oriented development offers promise as an
alternative to sprawl in urban regions, even though improvement in rates of
local shopping trips, walking, environmental sensitivity, and social interactions
remains unclear. Nevertheless, at this early stage, TOD, like ‘‘new urbanism,” is
still focused on development. Pairing it effectively with natural systems is an
obvious giant missing step in urban regions.Land protection and social pattern
Finally, land protection bears highlighting as a social dimension in
urban regions. The social interactions involved in the use of a common resource
are highlighted in the so-called ‘‘tragedy of the commons,” where land owned
in common is degraded by overuse. No-one feels responsible for it, and no