Don't blame residents of south Arlington or Mansfield for being impatient to see the expansion of Texas 360 become reality.The North Texas Tollway Authority agreed five years ago to build a toll road for the main lanes of the expanded highway between East Sublett/Camp Wisdom Road in Arlington south about 10 miles to U.S. 287 in Mansfield. Only the access roads are in place today.Texas 360 is a crucial north-south connection for the region, from Grapevine and the north entrance to Dallas-Fort Worth Airport to Arlington's entertainment district and on to Interstate 20. But south of the interstate, the main lanes disappear and traffic switches over to the access roads.NTTA's agreement to build a tollway from there to Mansfield was part of its "five in five" promise to build five major roadways within five years. The agency reinforced that commitment when it won the right to build a lucrative toll road in the Texas 121 corridor in Denton and Collin counties, now called the Sam Rayburn Tollway.Fast forward, and still no Texas 360. Not good.Fort Worth's Bill Meadows, a former NTTA board member now on the state Transportation Commission, says the agency has made "valiant" efforts to get started on the road.The project still does not have needed environmental clearance. If that happens by spring, the road could be built by 2017, Meadows says. Isn't that five more years?Meadows also says NTTA may have to take on private partners to pay for the Texas 360 extension.NTTA board member Victor Vandergriff of Arlington says he expects issues surrounding Texas 360 "to be cleared up here in the next couple of months."That would be good. The pressure is building.