摘要：The US parking infrastructure is vast and little is known about its scale and environmental
impacts. The few parking space inventories that exist are typically regionalized and no
known environmental assessment has been performed to determine the energy and
emissions from providing this infrastructure. A better understanding of the scale of US
parking is necessary to properly value the total costs of automobile travel. Energy and
emissions from constructing and maintaining the parking infrastructure should be
considered when assessing the total human health and environmental impacts of vehicle
travel. We develop five parking space inventory scenarios and from these estimate
the range of infrastructure provided in the US to be between 105 million and
2 billion spaces. Using these estimates, a life-cycle environmental inventory is
performed to capture the energy consumption and emissions of greenhouse gases, CO,
SO2,
NOX, VOC (volatile organic
compounds), and PM10 (PM: particulate matter) from raw material extraction, transport, asphalt and
concrete production, and placement (including direct, indirect, and supply chain
processes) of space construction and maintenance. The environmental assessment is
then evaluated within the life-cycle performance of sedans, SUVs (sports utility
vehicles), and pickups. Depending on the scenario and vehicle type, the inclusion
of parking within the overall life-cycle inventory increases energy consumption
from 3.1 to 4.8 MJ by 0.1–0.3 MJ and greenhouse gas emissions from 230 to 380 g CO2e by
6–23 g CO2e per passenger kilometer traveled. Life-cycle automobile
SO2 and
PM10 emissions show some of the largest increases, by as much as 24% and 89% from the baseline
inventory. The environmental consequences of providing the parking spaces are discussed as
well as the uncertainty in allocating paved area between parking and roadways.
