Smithsonian Magazine on MSN7 天
Chaotic Traffic From Horse-Drawn Carriages Inspired the World’s First Traffic Lights
Initial reactions to the signal, installed in London on this day in 1868, were mixed. Then, a freak accident scrapped the ...
BBC1 年
Signal failure: The two words dreaded by every commuter
Railway signals are traffic light devices that tell a train driver ... But sometimes these systems break and the signal turns red even when there is no train in the section. Signal failure refers ...