They're technically for offroad use only. And should be covered when driving on the road. Although unless you're being a jerk about blinding people I doubt you'll get attention.
I have mine wired to a switch, and to my high beams. But getting power direct from the battery through a relay. So when my high beams are on, the hellas are on, when I go to low beams they go off. That way I don't have to deal with two switches for traffic. I then also have a switch I can flip to completely disable the hellas.