Following up on Tuesday’s editorial about planned new toll lanes on Interstate 30 between Arlington and downtown Dallas, it looks like the lanes will provide a pretty good chunk of change to help pay for other transportation projects in North Texas.The North Central Texas Council of Governments tells the Star-Telegram Editorial Board that income from the project is expected to ramp up quickly and begin producing revenue that exceeds its maintenance and operation costs within one year after it opens for traffic. Revenue in Year 2 and Year 3 would recover the operating loss from Year 1, and for the next 20 years the toll lanes would gain “excess revenue” totaling around $240 million, NCTCOG projections show. The I-30 toll lanes represent an evolution in Texas toll projects. A decade ago, when it became clear that traditional sources of transportation revenue would fall short of meeting the need for more roadways, plans were made for more toll roads to help fill the gap.At the same time, many Texans strongly objected to making toll roads out of roads that had already been built with tax money, despite the revenue it would provide. That attitude has changed on I-30. The planned toll lanes there were built with tax money and initially designated as high-occupancy-vehicle lanes when the $166 million “Three Bridges” project was completed in 2010.That massive I-30 reconstruction effort was given high priority and was finished in time for Super Bowl XLV in Arlington.Years earlier, in 2006, the Federal Highway Administration had approved plans to charge tolls for single-occupant vehicles on the future I-30 HOV lanes.The HOV lanes currently are closed while a contractor completes $63 million in transition work, including limited entry and exit points and electronic TollTag/license plate readers.Transportation officials won’t reopen as toll lanes until 2015 or later, depending on possible reconstruction of the I-30/I-35E intersection in Dallas.If projections are correct, the “excess revenue” starts not long after the grand reopening.