Area-wide ANPR coverage with a small number of instrumented vehicles

The paper investigates the applicability of an area-wide coverage of speed enforcement by a non-stationary Automatic Number Plate Recognition (ANPR) system. Two instrumented cars, each fitted with an ANPR camera and related equipment, were facilitated in the surveys. These cars were parked systematically according to a schedule during the day within a large university campus in Turkey on 11 corridors over a four-month period. The work was carried out at two stages to be able to compare the effectiveness of the application. During the first two months, the application was disguised from the drivers. In the next two-month period the public were informed of the scheme by various publicity means and were told to obey the speed limits. Since the tests were carried out within a closed area, in both stages more or less the same profile of drivers were studied, hence the findings are expected to reflect directly the effects of the application. It was found that in most corridors the average speeds were lower in the second stage. For the two month period after the announcement of the scheme, no evidence was found to show that the impact was diminishing, suggesting the effectiveness of the system. However, the study revealed the problem of posting unsuitable speed limits in the campus which requires further attention.