Red Light Camera - Operation


Red light cameras are typically installed in protective metal boxes attached to poles at intersections, which are often specifically chosen due to high numbers of crashes and/or red light running violations. Red light camera systems typically employ two closely spaced inductive loops embedded in the pavement just before the limit line, to measure the speed of vehicles. Using the speed measured, the system predicts if a particular vehicle will not be able to stop before entering the intersection, and takes two photographs of the event. The first photo shows the vehicle just before it enters the intersection, with the light showing red, and the second photo, taken a second or two later, shows the vehicle when it is in the intersection.

Details that may be recorded by the camera system (and later presented to the vehicle owner) include: the date and time; the location; the vehicle speed, and the amount of time elapsed since the light turned red and the vehicle passed into the intersection. The event is captured as a series of photographs or a video clip, or both, depending on the technology used, which shows the vehicle before it enters the intersection on a red light signal and its progress through the intersection. The data and images, whether digital or developed from film, are sent to the relevant law enforcement agency. There, the information is typically reviewed by a law enforcement official or police department clerk who determines if a violation occurred and, if so, approves issuing a citation to the vehicle owner who may challenge the citation.

Studies have show that 38% of violations occur within 0.25 seconds of the light turning red and 79% within one second. A few red light camera systems allow a "grace period" of up to half a second for drivers who pass through the intersection just as the light turns red. Ohio and Georgia introduced a statute requiring that one second be added to the standard yellow time of any intersection that has a red light camera which has led to an 80% reduction in tickets since it's introduction. New Jersey has the strictest yellow timing provisions in the country as a result of concerns that cameras would be used to generate revenue, they have a statute specifying that the yellow time for an intersection that has a red light camera must be based on the speed at which 85% of the road's traffic moves rather than be based on the road's actual speed limit.

Read more about this topic:  Red Light Camera

Famous quotes containing the word operation:

    It requires a surgical operation to get a joke well into a Scotch understanding. The only idea of wit, or rather that inferior variety of the electric talent which prevails occasionally in the North, and which, under the name of “Wut,” is so infinitely distressing to people of good taste, is laughing immoderately at stated intervals.
    Sydney Smith (1771–1845)

    An absolute can only be given in an intuition, while all the rest has to do with analysis. We call intuition here the sympathy by which one is transported into the interior of an object in order to coincide with what there is unique and consequently inexpressible in it. Analysis, on the contrary, is the operation which reduces the object to elements already known.
    Henri Bergson (1859–1941)

    Human knowledge and human power meet in one; for where the cause is not known the effect cannot be produced. Nature to be commanded must be obeyed; and that which in contemplation is as the cause is in operation as the rule.
    Francis Bacon (1560–1626)