Cars that drive themselves are no longer just a concept you'd see in sci-fi movies imagining the near future. Companies like Waymo are already using self-driving cars, and you can ride in a robotaxi ...

You may have noticed some traffic lights with a white light that works independently of the others. They're not for normal cars; here's what they're for.

They might be vertical, they might be horizontal, but otherwise, traffic lights have hardly changed in a hundred years. Red means stop, yellow means slow down, and green means go, a universal code ...

Traffic engineers are quietly working on a radical idea: adding a white signal to the familiar red, yellow, and green. Instead of signaling drivers directly, the extra light would tell humans when to ...