A report in St. Louis says the State Transportation Department is considering turning Interstate 70 into a toll road that would cost motorists $20 to make a round trip between St. Louis and Kansas City. The St. Louis Post-Dispatch says truckers would pay $45 for that round trip. The study with those recommendations is expected out later this month. The Legislature and voters would have to approve a constitutional change to allow toll roads. A MoDOT spokesman tells the newspaper a toll system might be the only way to pay for a new 6-lane I-70 – which would cost an estimated $3-Billion.