It also might be the lights themselves on the track. Most cars these days use those LED day lights, and they only project light forward, rather than all around. So when the cars go over bumps, the cameras pick up the lights because it is being shown at them, this makes it looks like the lights are flashing. I noticed this when I was watching the GT3s at last years British GP. When the cars turned the corner in front of us, it appeared as though their lights were turning off.
Of course they may also flash theyre lights at other drivers to warn them but I was just offering another possible cause
