However, with steady blue lights the patrol car will likely just pass by you. Conversely, anytime you see flashing lights on a police cruiser it means the officer could be responding to an ...

Bismarck, North Dakota, followed in 2018, outfitting most of its intersections to help police spot red-light violations from a distance. These blue confirmation lights aren't one-size-fits-all.

By the 1960s, the red-and-blue combo became standard in many departments across the country. Over time, the big, clunky “gumball” lights were replaced with sleeker, more advanced light bars.