Modern MBT Headlights

The_Chieftain: Near as I can tell, the thinking behind the single lens on M1 was that if you were in a tactical environment, you would never need the white-light lens, and if you were in a garrison environment, you would never need the IR lens.   Of course, reality was that we would have to swap around as necessary in Iraq, depending on whether we were low-viz or high-viz.   Yes, many tanks do indeed have turn signals.