Environmental justice advocates face cantankerous legal questions as they come to grips with transportation issues.
Environmental justice has become a major issue for planners, funding agencies, and local communities involved with transportation projects. Today, such projects as highways, urban mass transit systems, and airports cannot pass muster without first coming under the watchful eyes of environmental justice advocates. A highly visible example occurred this summer when a federal appeals court stayed Atlanta's $19 billion, 25-year transportation plan, which the U.S. Environmental Protection Agency had already approved.  Environmental and civil rights groups had filed the lawsuit, complaining that the plan focused too much on the mostly white, affluent northside of Atlanta and too little on older urban neighborhoods, in violation of the transportation conformity provision of the Clean Air Act. 
Since President Clinton issued an executive order on environmental justice in 1994, requiring federal agencies to make environmental justice a part of their mission,  and especially since the U.S. Department of Transportation issued its own order in 1997,  expanding on the executive order, federally funded or approved transportation projects have come under increasing scrutiny over environmental justice concerns. This scrutiny will only increase in the future as environmental justice reviews of transportation projects will be routinely conducted, pursuant to a recent order issued by the Federal Highway Administration and the Federal Transit Administration.  In short, understanding and achieving environmental justice in transportation projects will be a critical challenge for many years to come.
Environmental justice is one of the most loaded expressions in the political lexicon. It is also notoriously difficult to define. In theory, environmental justice involves the "fair treatment and meaningful involvement of all people regardless of race, ethnicity, culture, income or educational status, with respect to the development, implementation, and enforcement of environmental laws, regulations, and policies."  In practice, environmental justice demands that federally funded transportation projects with negative environmental impacts not be dumped in areas where the local residents are predominantly minority or low-income citizens.
Applying environmental justice to transportation projects is an especially difficult proposition, perhaps best illustrated by considering highway projects. Highways are not discrete facilities that fit into relatively small, circumscribed areas. On the contrary, highways are large, sinuous structures that traverse many neighborhoods and affect members of various ethnic groups. Determining whether particular groups, such as minorities or those who live on low incomes, are disproportionately harmed by these projects can be extremely difficult.
Fortunately, three sets of legal rules help shed some light on environmental justice issues:
* Title VI of the Civil Rights Act of 1964, 
* the National Environmental Policy Act of 1969 (NEPA), 
* a series of administrative documents issued by DOT and two of its agencies, the Federal Highway Administration and the Federal Transit Administration.
Given the high profile of environmental justice issues, it is increasingly important for planners, funding agencies, funding recipients, and local communities to understand just what the law requires. Unfortunately, the law is in such an early state of development that it is easier to pose the questions than to suggest the correct answers.
The current prominence of environmental justice as an issue for transportation projects stems in part from a recent wave of "disparate impact" litigation under Title VI, which prohibits discrimination on the basis of race, color, or national origin under any activity receiving federal funds. …