Historical clue formulations

• Route: Abbr. — 2021-04-13
• Line on a map: Abbr. — 2020-04-19
• Numbered rd. — 2018-04-11
• What may take its toll?: Abbr. — 2018-01-11
• Any I, e.g.: Abbr. — 2017-04-22
• Artery: Abbr. — 2016-06-30
• It may take a toll: Abbr. — 2016-05-22
• Any I, e.g.: Abbr. — 2015-12-19
• U.S. 66, e.g.: Abbr. — 2015-07-05
• Interstate, e.g.: Abbr. — 2015-03-02
• Numbered rte. — 2010-11-09
• Rte. 66, e.g. — 2010-02-03
• Certain m.p.g. rating: Abbr. — 2009-03-22
• See 44-Across: Abbr. — 2007-06-30
• D.O.T. concern — 2002-05-10
• Rte. 66, e.g. — 1994-08-07