### Question
Can you define what maintenance area means?


### Answer
**Maintenance area** is defined as the following in *23 U.S.C. § 101*:

> an area that was designated as an air quality nonattainment area, but was later redesignated by the Administrator of the Environmental Protection Agency as an air quality 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**

