A group of Oregon trucking companies have sued the state and its top politicians, alleging that for years truckers have been charged more than their share of road taxes. The Oregon Trucking Association, along with companies Combined Transport, A&M Transport and Sherman Bros. Trucking, allege that they’ve footed a third of the taxes and fees paid by motorists, even though trucks make up only 15% of the state’s vehicles. They say the Oregon Constitution requires those costs be split according to how much each type of vehicle contribute to road wear and damage.