Event Data-Based Traffic Detector Validation Tests

Abstract

The accuracy of detector data is paramount for traffic surveillance, control, and information systems, yet little has been published on identifying or correcting errors in the data. This paper presents eight detector validation tests for freeway surveillance using individual vehicle data collected from loop detectors. Five of these tests can be applied to single-loop detectors, while all of them can be applied to dual-loop detectors. The tests are used to contrast the performances of different sensor models, and most of the tests are presented using 24-h blocks of data. In practice, they can also be used to identify permanent and transient hardware problems in other components of the detection system, for example, cross talk between loops or a short in the lead wires. For operational implementation, the tests could be modified to be applied hourly or after a fixed number of vehicles pass. Some of the tests can even be used to “clean up” erroneous measurements.