Traffic signal contractor? I know people that do it and made a hecuva lot of $ selling the old lights; yet I knew a guy who got killed doing it. (Semi truck knocked of bucket from arm.) If you want to do it, you'll be pulling wires under roads, through poles and mast arms, wiring the controller cabinets (nightmares), hanging and securing the lights by yourself, then wiring them. Oh, and you get to work in a bucket truck a lot. Still interested? Look in your phone book to see if there's a contractor (usually an EC) that does them. If there isn't, the township/state handle them.
Ian (Confusing people since 1997) A.