Answer:
A SigAlert, also written “Sigalert” and “SIG Alert,” is a term used by the California Highway Patrol (CHP) to describe traffic conditions that require closure of at least one lane for a minimum of 30 minutes. The term began as “Sigmon Traffic Alerts,” but was quickly shortened to “SigAlert.” The name comes from Loyd Sigmon, the inventor of the alert. The CHP issues SigAlerts in many ways, including electronic signs and announcements along the freeway, and announcements on radio and television.