Compact Development Could
Cut CO2 Emissions:
Higher Density, Mixed Use
Would Reduce VMTs
By Marcie Geffner
Doubling the density of
housing across a metropolitan area would reduce household vehicle miles
traveled (VMT), with a corresponding reduction in greenhouse gas (GHG)
emissions, according to a new study from the National
Academy of Sciences (NAS), a private nonprofit chartered by Congress.
NAS found that more
compact mixed-use development of residential and employment centers “is likely”
to reduce VMT and could directly and indirectly reduce energy use and CO2
emissions. The reduction in VMT could be as high as 25% through the following actions:
Double the
density of housing across a metropolitan area.
Double the
density of new and replacement housing and strategic infill.
The report suggests:
Smaller lots
for detached houses could shorten vehicle trip distances in low-density urban
fringes.
Smaller lots
and multiple-unit housing could support public transportation and encourage
walking and bicycling in moderate density suburbs.
Redevelopment
of strategically located underused parcels could support investment in rail
transit in urban-core areas.
The NAS also recognized
that compact mixed-use development on a large scale faces many obstacles, such
as restrictive local zoning ordinances, regional governments’ ineffectual land-use
regulation, and weak state involvement in land-use planning.