Motor vehicle. A self-propelled vehicle designed and used for transporting persons or property on a public way.

Opacity. The degree to which transmitted light is obscured, expressed in percent.

Person. An individual, public or private corporation, political subdivision, agency, board, department or bureau of the state, municipality, partnership, association, firm, trust, estate or any other legal entity whatsoever which is recognized by law as the subject of rights and duties.

Visible emissions. Gases or particulates, excluding uncombined water, which separately or in combination are visible on release to the outdoor atmosphere.