Red Flash Question

[Oswegowind 17]

I understand that the term, "RED FLASH" is used to indicate that only emergency/priority transmissions (i.e. radio silence {10-40 YPD}) is in effect, along the NYS Thruway system.

I have heard it used on a number of occasions...including jumper up/down TZB, fatal accident invol Tpr Ambrose in Yks., pursuit with suspect tossing drugs out of window on SB I-87 in Westchester County.

Where does the term come from? It seems a bit unusual in itself... Any info would be appreciated.

Edited May 15, 2007 by Oswegowind