OTHER ROAD, STREET, OR HIGHWAY PROJECTS.

(a) The commissioners court of a county or a local government corporation, without state approval, supervision, or regulation may:

(1) authorize the use or pledge of surplus revenue to pay or finance the costs of a project for the study, design, construction, maintenance, repair, or operation of roads, streets, highways, or other related facilities that are not part of a project under this chapter; and

(2) prescribe terms for the use of the surplus revenue, including the manner in which revenue from a project becomes surplus revenue and the manner in which the roads, streets, highways, or other related facilities are to be studied, designed, constructed, maintained, repaired, or operated.

(b) To implement this section, a county may enter into an agreement with the commission, the department, a local governmental entity, or another political subdivision of this state.

(c) A county may not take an action under this section that violates or impairs a bond resolution, trust agreement, or indenture that governs the use of the revenue of a project.

(d) Except as provided by this section, a county has the same powers, including the powers to finance and to encumber surplus revenue, and may use the same procedures with respect to the study, financing, design, construction, maintenance, repair, or operation of a road, street, highway, or other related facility under this section as are available to the county with respect to a project under this chapter.

(e) Notwithstanding other provisions of this section:

(1) any work on the state highway system must be approved by the department; and

(2) the department shall supervise and regulate any work on a highway in the state highway system.