Turning Left

UPS is famous now for having its delivery trucks avoid left turns. A driver will make three right turns to go around a block rather than sit and wait for a break in traffic to make a left. UPS says it’s saved millions of gallons of gasoline with this approach. It’s also safer since the majority of crashes that happen at intersections in the U.S. involve a left-hand turn. What if cities banned left turns? Or at least got rid of them at certain intersections? Penn State civil engineering professor Vikash Gayah has some new work identifying just how cities could maximize the benefits of eliminating left turns.