Research Activities of the Department of Transportation:
A Report to Congress
According to the report, there are five DOT objectives that guide the agencys research priorities: safety, mobility, global connectivity, environmental stewardship, and security. Most DOT priorities address more than one objective and are supported by several departmental programs.
Link
http://www.rita.dot.gov/publications/research_activities_of_the_department_of_transportation_a_report_to_congress/pdf/entire.pdf