In March, a truckers’ trade association and a drivers’ advocacy group filed a federal lawsuit arguing that turnpike tolls are at least 200 percent more expensive than they should be. The suit also contends that using toll revenue to fund transit violates the U.S. Constitution’s commerce clause, which regulates interstate commerce. It claims that toll money should go only toward maintaining the turnpike system and that Pennsylvania was wrong to allocate toll revenue for transit with laws passed in 2007 and 2013. The high tolls interfere with interstate trade, the suit argues.