Could you go into a little bit more detail about your driving route?
Is it pretty much the same, day to day? Do you travel by any airports on a routine basis?
Do you notice certain vehicle makes when these alerts occur? The reason I ask this one is that newer vehicles equipped with Adaptive Cruise Control (ACC) and Lane Departure warning systems often rely on either radar or lidar (laser) based systems to function. I found this to be true when the Audi Q9 with Side Assist.
Furthermore some vehicles like Lexis can set of laser detectors when their rear brake lights are activated.