Incorporating social and environmental values into transportation decision making. Describing, quantifying and evaluating alternate transportation benefits, costs and equity impacts.
Analysis of these impacts is essential to help determine: (1) The full benefits and costs of a transportation policy or program; (2) How to incorporate these impacts into the decision making process; and (3) The net benefits of alternatives, including transportation demand management strategies, different travel modes, new technologies, and alternative fuels.
Transport activities can contaminate soil, water and air, through accidents involving dangerous goods and contamination from transport infrastructures, or by heavy metals from vehicle exhausts, de-icing substances, fuel spillages, release of fuels and other pollutants from road and rail vehicles, ships and aircraft.
Transportation contributes 30 percent of the carbon dioxide emissions in the U.S and is second only to electric utilities in the emission of carbon dioxide. Carbon dioxide is projected to contribute more than 75 percent of enhanced global warming over the next century.
The following approaches are used to evaluate and develop less polluting transport policies: (1) Transport enabling programs, which provide a basis for the evaluation, implementation and ongoing review of traffic management policy; (2) Land use measures, which attempt influence where people live in relation to work and other common destination points; (3) Transport system management, which attempts to increase the person carrying capacity of the road system without building additional road capacity; (4) Transport demand management, which uses economic incentives, regulations and voluntary measures to influence the extent, timing and mode of travel; (5) Traffic calming measures, which describe various physical and design changes that allow roads to better accommodate a range of different road uses; and (6) Alternate mode transportation measures, which describe how conditions might be improved for pedestrians, cyclists and transit users.