Transportation: Environmental Challenges
According to the U.S.Environmental Protection Agency, transportation in 2007 represented 33% of U.S. carbon dioxide (CO2) emissions from fossil fuels. Transportation can also represent as much as 33% of household expenses for a low- and moderate income family. Chronic reliance on auto-dependent transportation strategies has brought with it a number of significant challenges.
Greenhouse gases (GHG) and emissions generally
- Private vehicle use contributes a significant share of GHG emissions.
- Excess CO2 and Nitrous Oxide (NOX) emissions can put a municipality or region in danger of non-compliance with federal clean air laws, resulting in the delay or cancellation of federal transportation funds.
- Human health is impacted by emissions, especially those who already suffer from respiratory disease.
Transit, car pooling and car sharing with fuel efficient vehicles can decrease GHG and other emissions. And walking and bicycling generate no pollution, as well as promoting good health and reducing obesity.
Fossil fuels
- Fossil fuels are a declining resource that needs to be conserved for the long term.
- Transportation’s dependence on fossil fuels makes the United States more vulnerable to supply disruptions arising from instability around the globe.
The United States is beginning a transition toward high efficiency vehicles, including hybrids, which use dramatically less fossil fuels. In coming years, electric cars are likely to become available that can be charged at night when electric demand and cost are very low.
Some municipalities are beginning to plan with their utilities for this transition through such ideas as “mobility stations” that would permit electric or hybrid electric car owners to charge their vehicles away from home, thereby extending their effective range.
Land use
- Transportation and land use are integrally related. The availability of transportation options, especially alternatives to auto dependence, permit denser and more efficient uses of urban land and, consequently, lower energy use.
- Sprawling land uses limit the mobility of populations like the young, the old, people with disabilities and households that cannot use or afford cars
- Regions that use land inefficiently may be less able to compete in a global economy because too many regional resources are committed to supporting auto-dependent land uses.
Many municipalities are actively encouraging transit oriented development that clusters multiple uses around transit hubs, including apartments, townhouses, retail, and city services. This efficient use of urban land both encourages alternatives to car use and supports a vital urban streetscape that is increasingly appealing to young adults, and others.
Impermeable surfaces
- High proportions of paved areas (wide lanes, parking lots) contribute to stormwater management problems by channeling rainwater into the stormwater system, rather than allowing rainwater to percolate directly into the soil.
- Impermeable surfaces also cause the toxins from streets and highways (oil, gasoline, tire and brake particles) to be flushed into the stormwater system where they have to be removed, in contrast to percolation, which can often use natural processes to neutralize such toxins well on a dispersed basis.
Green infrastructure strategies can decrease the cost of processing stormwater in treatment plants, especially where sewage and stormwater are combined. This approach to stormwater also shifts public resources into parks and open space, and supports a shift to native landscaping.
A method of transportation where people will collaborate on their driving needs in order to reduce the number of cars on the roads. An example of car pooling is co-workers who live near each other driving to work together.Allows more than 50% absorption of water.The system of land, natural resources, and natural habitats that collectively comprise a community's underlying ecosystem. Green Infrastructure is present in every city, although its size, diversity, and strength vary greatly. Importantly, green infrastructure can be used to help offset negative environmental impacts, for example stormwater runoff and urban heat island effect.Greenhouse gases are a part of the Earth's atmosphere and are both naturally occurring and the result of human chemical processes. The most common greenhouse gases are carbon dioxide, water vapor, methane, nitrous oxide, ozone, and chlorofluourocarbons. These gases trap heat and thus contribute to the warming of the planet. See also CFCS and GREENHOUSE EFFECT.Fuel formed from geological processes acting on the remains of living organisms. Typically refers to oil, coal, natural gas or their by-products.The ability or potential of a physical body to do work. The most common forms of energy are heat, light, mechanical (moving parts), and electrical.
