The term 'Highway Caution' can be broken down into five crossword solutions: SLO (3 letters), DIP (3 letters), NARROWING (9 letters), SLOW (4 letters), and SLIPPERYWHENWET (15 letters). SLO stands for 'Speed Limit Over' and is a warning to drivers that the speed limit is higher than usual. DIP is an acronym for 'Dangerous Intersection Ahead, ' which is a warning to drivers that they are approaching a hazardous intersection. NARROWING is a warning to drivers that the road is NARROWING, and they should be prepared to adjust their speed accordingly. SLOW is a warning to drivers to reduce their speed, as the road ahead may be hazardous. Finally, SLIPPERYWHENWET is a warning to drivers that the road may be slippery when wet, and they should take extra caution when driving in wet conditions.