Ramp Metering Signal Controls
Ramp meter signals are set according to the current traffic conditions on the road. Detectors (generally an induction loop) are installed in the road, both on the ramp and on the main road which measure and calculate the traffic flow, speed and occupancy levels. These are then used to alter the number of vehicles that can leave the ramp. The more congested the main carriageway the fewer vehicles are allowed to leave the ramp, this is effected by giving longer red times to the traffic signals.
Much research is currently being carried out into the most appropriate algorithms for controlling ramp meter signals. Some algorithms that are in use or have been evaluated are ALINEA, demand control and fuzzy algorithms.
Read more about this topic: Ramp Meter
Famous quotes containing the words signal and/or controls:
“Certainly the effort to remain unchanged, young, when the body gives so impressive a signal of change as the menopause, is gallant; but it is a stupid, self-sacrificial gallantry, better befitting a boy of twenty than a woman of forty-five or fifty. Let the athletes die young and laurel-crowned. Let the soldiers earn the Purple Hearts. Let women die old, white-crowned, with human hearts.”
—Ursula K. Le Guin (b. 1929)
“We’ve got to figure these things a little bit different than most people. Y’know, there’s something about going out in a plane that beats any other way.... A guy that washes out at the controls of his own ship, well, he goes down doing the thing that he loved the best. It seems to me that that’s a very special way to die.”
—Dalton Trumbo (1905–1976)