A complex network of public and private organizations finances, plans, builds and operates the U.S. transportation system. Every U.S. jurisdiction has an elected legislative body that is broadly responsible for policies, programs and, to some extent, appropriations and program oversight, and an agency or department within the executive branch that is responsible for highway functions under the authority of a governor or other lead executive. The organizational structures and functions of these entities, however, vary widely across jurisdictions.

Every U.S. jurisdiction has an elected legislative body and an executive department that is responsible for highway functions under the authority of a governor or other lead executive.

Most state DOTs are organized by divisions or organizational units based on functional activities such as administration, finance, planning, engineering, operations or construction.

Legislatures vary from those with year-round sessions, full-time legislators and large staffs (such as those in California, Michigan, New York and Pennsylvania) to those with limited or biennial sessions, part-time legislators and smaller staffs (such as those in Georgia, Idaho, Indiana, Kansas, Maine, Mississippi, Nevada, New Mexico, Rhode Island, Vermont and West Virginia). A legislature's overall characteristics and capacity will affect, but not necessarily dictate, the extent of its involvement in transportation governance. Vermont, for example-a state that has a part-time legislature with limited staff and compensation-has high legislative involvement in transportation issues.

State DOTs vary by organizational structure, modes served, balance between state and local roles, and general roles and responsibilities. They also vary by the practical division of roles and responsibilities between the governor and the DOT.