Green Building and LEED Core Concepts Guide First Edition

The drivers of transportation impacts include location, vehicle technology, fuel, and human behavior.
Location determines the number ·and frequency of trips. Vehicle technology determines me
quantity and types of energy and support systems needed to convey people and goods to and from
the site. Fuel determines the environmental impact of vehicle operation. Human behavior ultimately
combines all of these elements in daily mobilitychoices. Green building's emphasis on integrative
approaches calls forthe coordinated, synergistic consideration for each of these elements.
In practice, green building often assesses the elements of transportation through proxy measures
and metrics. For example, density stands in for many clements of.land-use design. Project sites in
urban areas are likely to have the density required for the sustainable operation of mass transportation-
systems that are less energy intensive than single-passenger vehicles. By building in a relatively
high density area or on an inflll site already served by mass transit, the project can reduce the
vehicle miles traveled byits occupants and visitors and more easily integrate into existing transportation
nenvorks.
Sites without access to public transportation start at a
disadvantage and may require additional attention to
transportation impacts, particularly local land-use design
and alternative fuels. It is still possible for such a project
to substantially reduce its transportation impacts by
focusing on local connectivity and the energy efficiency of
the vehicles used to serve its needs. For example, an office
complex without transit access might provide incentives for
carpooling, incorporate diverse land uses that allow workers
to walk to basic services, or facilitate the use of alternativefuel
vehicles like plug-in hybrids.
Consideration for transportation provides many opponunities for integrative planning, such as
specifications for parking. Typically, parking is sized for annual extreme events, like shopping on
the dayafterThanksgLvingj during the other364 days of the year, parking capacity is unused, and unnecessary
expanses of asphalt or concrete have environmental impacts, causing urban heat islands
and storm\Vater runoff. A project team can reduce the number of parking spaces provided for singlepassenger
vehicles, thereby discouraging vehicle use, reducing environmental impacts, and loweringthe
cost of construction. Project teams cango funher and designate preferred parking spaces for
altcrnative-fuel vehicles. Incentives for low-impact behavior may become more appealing as technologies
like plug-in hybrids become more common.
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Green Building and LEED Core Concepts Guide