Environmental justice is an increasingly important element of policy making in transportation. It is not specific to any mode of transportation, particular community, or single policy issue. It is fundamentally about fairness toward the disadvantaged and often addresses the exclusion of racial and ethnic minorities from decision making. The federal government has identified environmental justice as an important goal in transportation, and local and regional governments must incorporate environmental justice into transportation programs. Because ideas about justice differ between communities, local and regional governments have flexibility in how they change their policies to reflect environmental justice. Communities and local governments struggle to balance competing interests and interpretations of environmental justice. To parents living in a neighborhood with a lot of bus service, environmental justice might mean converting buses from diesel to natural gas, reducing their children’s exposure to air pollution. A security guard working the night shift might feel that environmental justice has been served if the bus she takes deviates from its regular route to drop her off closer to home. Environmental justice to a non-English speaking neighborhood might mean having bilingual staff and community leaders running a public meeting. To low-income workers relying on bus service in a large downtown, environmental justice might mean that a city increases the frequency of buses instead of building a new light rail line that would serve upper-income commuters. In short, there is no single definition of environmental justice: its meaning depends on context, perspective and timeframe. Environmental justice issues arise most frequently when: Some communities get the benefits of improved accessibility, faster trips, and congestion relief, while others experience fewer benefits; Some communities suffer disproportionately from transportation programs’ negative impacts, like air pollution; Some communities have to pay higher transportation taxes or higher fares than others in relation to the services that they receive; or Some communities are less represented than others when policy-making bodies debate and decide what should be done with transportation resources. Racial and ethnic minority groups, low-income people, the elderly, and people with disabilities have all been the victims of environmental injustices in transportation. Sometimes an affected community is primarily geographic, consisting of those living in a particular corridor or in a neighborhood near a certain transportation facility. Or those affected might share similar racial, ethnic, or economic characteristics. These groups are often referred to as “environmental justice communities.” But because power and needs change over time and space, the term “environmental justice communities” is problematic. Environmental justice is used to protect the needs of the powerless, whomever they might be, and as they change. Many community members are becoming involved with transportation decisions that impact their mobility needs, health, and overall quality of life. A member of the public concerned with environmental justice might be involved with making transportation decisions as: A citizen appointed to an environ-mental justice task force or committee; A member of a disempowered group, representing the group’s interests to an advisory committee for the purpose of discussing and influencing transportation policy choices; A member of an advocacy group active in transportation issues; An employee of a non-profit agency that wants to be involved because of the effect that transportation policies have on its constituents; or A resident or business owner affected by a transportation decision. Although there is no substitute for the knowledge that can be gained over time through experience, this handbook will help those who are new to transportation decision processes influence how environmental justice is incorporated into decisions about transportation policy and projects. Various approaches to environmental justice are discussed, along with steps in the planning process when citizen involvement is particularly effective, suggestions for how environmental justice can be incorporated into a project, and legal requirements for environmental justice.