Historical clue formulations

• Driving hazards — 2020-02-28
• Road hazards that need filling — 2019-01-07
• Things filled by a highway crew — 2018-09-17
• Road hazards ... four of which are illustrated literally in this puzzle — 2015-10-22
• Results of road fatigue — 2010-05-15
• They cause jolts to bolts — 2003-11-13