Urban mobility problems demand clarity. Intersections remain the most common sites for crashes, congestion, and violations.

Some things are so ubiquitous that it's easy to forget they're designed for a reason. With more than 300,000 traffic lights set up across the United States, it's easy to take how they look for granted ...

Q: Do you need to come to a complete stop before turning right at an intersection when the light is red, if the red traffic signal is located across the intersecting street for vehicles proceeding ...