In this chapter:
(1) "Cost" includes an expense of engineering and other expense incident to construction of an improvement.
(2) "Governing body" means the governing body of a municipality.
(3) "Highway" includes any part of a street, alley, public place, or square, including a part left wholly or partly unimproved in connection with another street improvement.
(4) "Improvement" includes the following, liberally construed:
(A) filling, grading, raising, paving, or repairing a highway in a permanent manner;
(B) constructing, realigning, or repairing a curb, gutter, or sidewalk;
(C) widening, narrowing, or straightening a highway; and
(D) an appurtenance or incidental to an improvement, including a drain or culvert.