The Georgia Department of Transportation will close a portion of northbound I-985 in Gwinnett County at night this weekend as construction continues on new I-85 express lanes.

All northbound lanes of I-985 will be closed at the I-85 split from 9 p.m. to 5 a.m. Friday, Saturday and Sunday nights while GDOT places concrete bridge beams. Northbound traffic will be detoured onto I-85 to Exit 115, then on Ga. 20 northbound and back to I-985 at Exit 4. The exact dates could change because of weather and other factors.

Southbound traffic on I-985 will not be affected.

GDOT is extending the I-85 express lanes from Old Peachtree Road to Hamilton Mill Road.