Electrical contractors working for the state no longer have to pay state use tax on certain components of traffic lights after the Pennsylvania Supreme Court on Thursday upheld a lower court decision that poles, mast arms and pedestal bases constitute "traffic signals" and are therefore exempt under the Tax Reform Code. 

According to one of the lawyers on the winning side in the case, the decision reinforces a trend of the Commonwealth Court allowing for broader interpretation of tax exemptions for construction materials and will provide better guidance to companies working for the state on whether their materials are subject to sales tax.