Historical clue formulations

• Like some winter windshields — 2020-08-15
• Became impassable, in a way — 2019-07-27
• Slick, in a way — 2014-06-21
• Became a winter hazard, as a road — 2012-03-12
• Needed a coating of heated propylene glycol, say — 2009-09-05
• Jammed, in a way — 2002-11-29
• Frosted — 1996-07-25