Dallas North Tollway drivers should brace for detours and slowdowns over the next two weekends as construction crews prepare to close an entire stretch of the busy thoroughfare starting Friday.

The North Texas Tollway Authority on Tuesday announced the closures, which are part of a project to expand the tollway to four lanes in each direction. The closures will facilitate the reconstruction of the Tennyson Parkway bridge over the tollway and the addition of a U-turn lane at Legacy Drive.

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.

Crews are also planning another full closure of the same stretch of the Dallas North Tollway starting 11 p.m. Aug. 18 through 5 a.m. Aug. 21.

This weekend's closure is part of the reconstruction of the Tennyson Parkway bridge, which crosses over the tollway lanes, according to the tollway authority. The following weekend's closure will be to construct an extra U-turn lane at Legacy Drive, where city of Plano officials plan to one day install a pedestrian and bike bridge connecting the city's burgeoning Legacy West development with The Shops at Legacy.

Click here for a detailed breakdown of this weekend's lane closures and detours, courtesy of the North Texas Tollway Authority.