### Question
How does AID HIGHWAYS define maintenance area?


### Answer
Under *23 U.S.C. § 101*, **maintenance area** is defined as:

> an area that was designated as a nonattainment area, but was later redesignated by the Administrator of the Environmental Protection Agency as an attainment area, under section 107(d) of the Clean Air Act (42 U.S.C. 7407(d))

#### Citation:
  - *23 U.S.C. § 101*
  - Heading: **CHAPTER 1-FEDERAL-AID HIGHWAYS > SUBCHAPTER I-GENERAL PROVISIONS**

