As construction along the Dallas North Tollway improvement project continues, nightly lane closures are expected to occur this week southbound from I-635 to I-35E. Drivers can expect two southbound left lanes to close along the DNT from south I-635 to I-35E from April 17 to Friday, April 21. The lane closures will take place nightly from 10 p.m.-5 a.m. Delays are expected and drivers are urged to use caution in the construction area, according to the North Texas Tollway Authority. This construction will replace the tollway's center barrier, pavement and pavement markings along with restriping the main lanes. The project is expected to be complete by late 2018, according to the NTTA.