Sometimes we get green lights, and sometimes we hit all the red lights on our commute to work. But, while sitting at a red light, have you ever wondered why traffic lights are red, yellow ...

Modern traffic lights all use the red, amber, green system Credit: Alamy Before cars were commonly in use train drivers needed a way to navigate the growing railway. On the original train system ...

Eventually, the upgrades could do away entirely with the red, yellow and green lights of today, ceding control to driverless cars. Henry Liu, a civil engineering professor who is leading a study ...

It published the Manual on Uniform Traffic Control Devices, which set standards for all signs and signals. This manual decided all traffic lights had to be red, yellow and green.

Eventually, the upgrades could do away entirely with the red, yellow and green lights of today, ceding control to driverless cars. Henry Liu, a civil engineering professor who is leading a study ...