J-Rooster wrote:
...A long time ago when I took a CDL test at the DOL that light flashing was a question on the test that I took. I was amazed to find out it is against the law. How do I know this? I answered the question incorrectly and said it was O.K. to flash headlights. The DOL Officer told me if you flash a truck to pull in front of you and a accident occurs from that result, you are responsible for that accident by signaling to the truck that it is O.K. to pull in. I have never in my 44-1/4 years driving OTR heard of anyone being cited for flashing there head lights. Good Question
I think your DOL officer may have been wrong. The reason flashing lights is illegal in some states is because many people used to do it to warn oncoming traffic of speed traps. Yes, that flashing of lights may be illegal in certain states. I don't think it applies to lane changing.
Is it possible that your DOL officer misunderstood this?
I would have asked him, what lawful purpose do these buttons provided to us by the manufacturers have? I can assure you that manufacturers would not provide equipment on board that has no lawful purpose.