Presidential Executive Order 12898 on Environmental Justice (EJ) was signed in 1994, and the U.S. Department of Transportation (DOT) issued regulatory guidelines for addressing EJ in transportation in 1997. Transportation agencies have since adopted a range of policies, programs, and activities to identify and address disproportionately high and adverse human health and environmental effects of their policies, programs, and activities on minority and low-income populations. On the basis of the relevant literature and structured interviews, this paper assesses how state DOTs are addressing EJ issues in their decision-making processes and identifies common and effective practices. The results show that several state DOTs have implemented public involvement programs and other procedures to assess the burdens of transportation investment. However, fewer agencies assess the equity of benefits, fewer assess outcomes of EJ actions, and fewer still link EJ analysis outcomes with future funding and policy decisions. On the basis of existing practices and regulatory guidelines, the researchers formulated a performance-based, maturity-scale model that agencies can use to benchmark the effectiveness of their external and internal EJ activities in achieving EJ outcomes in transportation. The model was applied anonymously to selected agencies to demonstrate different maturity levels in addressing EJ.