[mav1178]

Originally Posted by Marchy

I did not know that was law, i just did that because common sense tells me if visibility is reduce, say by rain, i need to make myself as bright and visible as possible. (without blinding people obviously)

It varies by state. Not law in WA but in many other states it's a requirement (or if visibility is low):
http://drivinglaws.aaa.com/laws/headlight-use/

-alex