Historical clue formulations

• Sign of the cross? — 2016-12-10
• Caution for drivers on city streets — 2015-07-26
• Something often seen on a street corner, briefly ... or, literally, something seen in each corner of this puzzle — 2014-12-22
• Warning about people moving from side to side? — 2008-03-15
• Traffic caution — 2006-01-01