What is the primary function of high visibility vests when working at roadway crash scenes?

The primary function of high visibility vests at roadway crash scenes is to ensure visibility and safety. These vests are designed with bright colors and reflective materials to make personnel easily seen by drivers and others present at the scene, particularly in low-light or high-traffic conditions. This increased visibility is crucial for protecting EMS workers from accidents, as they may be working in potentially hazardous environments where moving vehicles are present. By wearing high visibility vests, EMS personnel can significantly lower the risk of injury to themselves while performing their duties in unpredictable settings.