ARLINGTON — A new stretch of the President George Bush Turnpike opens this weekend, giving motorists who are willing to pay a toll a true alternative to congestion on Texas 360 in the Arlington-Grand Prairie area."It will be a vast area connecting to south Arlington and Mansfield. It has been a long time coming, and it feels great spending all these years working to get projects done," said Victor Vandergriff of Arlington, a North Texas Tollway Authority board member.Weather permitting, the new 6.5-mile western extension of the turnpike from Egyptian Way which is just north of Interstate 30 to Interstate 20 will be open by Monday morning rush hour, tollway officials said. The extension was originally known as Texas 161, but in 2010 the tollway authority took over construction of the project from the Texas Department of Transportation.The speed limit initially will be 70 mph, although tollway officials say theyll conduct a speed study to determine a permanent speed. Speed limits will be lower in construction areas, as workers put the final touches on the project by spring. For example, the frontage roads are still under construction at the railroad crossings between Main and Jefferson Streets in Grand Prairie, and scheduled to open by the end of the year. Also, interchange with I-30 eight direct-connector ramps, but only five will be completed by this weekend, with the other three scheduled to open by spring.The Bush Turnpike western extension is a north-south road, running parallel to Texas 360 about two miles to the east. It gives motorists willing to pay a toll a legitimate alternative to sitting in congestion. On Texas 360, traffic regularly grinds to a halt at Division Street in east Arlington, and at Texas 183 in Irving. With the opening of the western extension, the Bush Turnpike will now be 52 miles long, stretching across the northern half of the greater Dallas area.