Origin
Before the mid 1980s, Pittsburgh had a non-standard traffic light sequence. The green light would become simultaneous green/yellow, then just yellow, and finally red. While some believe this sequence reduced the chances of cross-traffic running the red light immediately before the anticipated green, and thus encouraged early left turning, this practice is also observed in other regions with no history of simultaneous green and yellow. Some large intersections have four-way red for several seconds as a safety buffer, providing an opportunity for an illegal and unsafe left turn after cross-traffic has physically stopped but before the green light gives legal right of way.
Read more about this topic: Pittsburgh Left
Famous quotes containing the word origin:
“In the woods in a winter afternoon one will see as readily the origin of the stained glass window, with which Gothic cathedrals are adorned, in the colors of the western sky seen through the bare and crossing branches of the forest.”
—Ralph Waldo Emerson (1803–1882)
“For, though the origin of most of our words is forgotten, each word was at first a stroke of genius, and obtained currency, because for the moment it symbolized the world to the first speaker and to the hearer. The etymologist finds the deadest word to have been once a brilliant picture.”
—Ralph Waldo Emerson (1803–1882)
“Good resolutions are useless attempts to interfere with scientific laws. Their origin is pure vanity. Their result is absolutely nil. They give us, now and then, some of those luxurious sterile emotions that have a certain charm for the weak.... They are simply cheques that men draw on a bank where they have no account.”
—Oscar Wilde (1854–1900)