intersections, which are often specifically chosen due to high numbers of crashes and/or red-light-running violations. In some case, cameras are built into traffic lights. Red light camera systems typically employ a sensor that detects the presence of a vehicle past the stop bar, and, in some cases, measures the speed of a vehicle at the time it ran the red light. The sensors may be single or dual inductive loops, piezoelectric strips, laser, radar or optical video analyses. Using the speed measured, the system predicts if a particular vehicle will not be able to stop before entering the intersection. In some instances the system takes two or more photographs. 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, the amount of time elapsed since the light turned red, and the amount of time elapsed since the light turned yellow 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 shown 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 its introduction. New Jersey has the strictest yellow timing provisions in the country as a result of concerns that cameras