In this subchapter:
(1) "Day" means a calendar day.
(2) "Federal Highway Administration" means the United States Department of Transportation Federal Highway Administration.
(3) "Highway project" means a highway or related improvement that is:
(A) part of the state highway system; or
(B) not part of the state highway system but funded wholly or partly by federal money.
(4) "Local government sponsor" means a political subdivision of the state that:
(A) elects to participate in the planning, development, design, funding, or financing of a highway project; and
(B) is a municipality or a county, a group of adjoining counties, a county acting under Chapter 284, a regional tollway authority operating under Chapter 366, a regional mobility authority operating under Chapter 370, a local government corporation, or a transportation corporation created under Chapter 431.