Hundreds of traffic signals in the District will be retimed over the next week or so in an effort to improve traffic flow and pedestrian safety.

The District Department of Transportation said in a statement Friday that 436 intersections would be retimed in an area bounded by the Potomac River to the west, the D.C.-Maryland border to the north, Clifton Street Northwest to the south and the Georgia Avenue and North Capitol Street corridors to the east. The lights being retimed are spread across Wards 1, 2 and 4 and include Georgetown, Columbia Heights and parts of Adams Morgan.

In addition to the new timing, DDOT said, they’ll be adding Leading Pedestrian Intervals — “walk” signals that give pedestrians a few extra seconds before cars going in the same direction get a green light — in 207 more intersections, as well as Pedestrian Signal Recall — automatic signals that don’t require a pedestrian to push a button to get the “walk” signal — in 58 more, and longer pedestrian crossing times at 97 more intersections.

New timing plans will also be different during late-night hours, and will take into account the new default speed limit on D.C. streets.

DDOT said that they’re using data on traffic from cars, bikes, transit and pedestrians to make the changes, the first since 2016.