The Department of Transportation is wasting no time in implementing improvements on 4th Avenue in Park Slope now that the community board finally approved it last month. Construction will begin August 19, according to a flyer sent out by the DOT. The main point of the changes is to improve safety for drivers and pedestrians. Toward that end, left turns will be eliminated at six intersections, including 9th Street and 3rd Street. Speed humps and painted curb extensions will be added at 5th Street. Pedestrian medians at 9th Street will be widened to allow safer crossing near subway stations. South Slope News was the first to note the construction date.