Portions of the Dallas North Tollway will be closed at the Sam Rayburn Tollway juncture Aug. 18-21.[/caption] Weather permitting, crews will continue construction on the Dallas North Tollway for the second weekend in a row—shutting down an entire stretch of the busy thoroughfare starting Friday. The North Texas Tollway Authority Tuesday announced the closures to pour concrete for a new U-Turn at the Legacy Drive overpass. City of Plano officials plan to use the former U-Turn lane as a pedestrian and bike bridge connecting the city’s burgeoning Legacy West development with The Shops at Legacy. Partial closures begin Friday, when crews will close two of the tollway’s three lanes in each direction from 9-11 p.m. over an extent of road stretching roughly from Sam Rayburn Tollway to Spring Creek Parkway. All lanes will close at 11 p.m. Friday before they reopen 5 a.m. Monday in time for most morning commutes. Last weekend's construction on Aug. 11-14 was part of the reconstruction of the Tennyson Parkway bridge, which crosses over the tollway lanes, according to the tollway authority.