The term 'WARNING TO DRIVERS' can be summarized by two crossword solutions: SLO (3 letters) and SIREN (5 letters). SLO stands for 'speed limit ooperations, ' which is a type of police enforcement that involves officers monitoring speed limits in order to reduce the number of traffic violations. SIREN is an acronym for 'sound-producing instrument for emergency notification, ' which is a device used to alert drivers of potential danger or hazardous conditions. Together, these two solutions indicate that drivers should be aware of their speed and be prepared to respond to any warnings they may receive.