City of Fairfax police have introduced a new ‘cruise mode’ for police lights. They are different from the flashing emergency lights and are designed to "enhance the presence of police vehicles, especially during evening hours or in low-light situations.”
The "cruise mode" lights are steady burning and will be lit while on patrol.
The City of Fairfax Police Department said, quote, “Unlike the usual flashing emergency lights, and siren, that indicate an urgent situation, the ‘cruise mode’ lights are steady burning and do not signify an emergency. There is no need for you to stop or yield unless directed by an officer.”
They shared this video to show the difference between Emergency Response Lights & Cruise Mode lights:
Source: WTOP