In 2016 and 2017, New York City installed infrastructure designed to slow down drivers making left-hand turns in more than 200 locations and banned left turns at high-risk spots as a way to curb pedestrian crashes. Since then, median left-turn speeds have dropped 19 percent at those intersections and the number of vehicles cutting turns so closely they cross the double yellow lines declined by 79 percent. Now cities like San Jose and Los Angeles are looking to follow New York’s lead.