Aggregated navigation system data can be used by an artifact repository to
infer the presence of a static traffic artifact. Static traffic artifact
can include traffic lights, traffic signs, special traffic zones,
railroad crossings, and the like. Metric data collected from multiple
global positioning systems (GPS) devices can provide sampling data for
inferring a static traffic artifact on a road. Metrics can include
driving behavior, travel direction, velocity, timestamps, delay, and the
like. For example, if thirty percent of the data collected about an
intersection indicates drivers come to a stop at an intersection, the
system can infer a traffic light exists at the intersection. Each traffic
artifact can have an associated confidence factor which can indicate the
degree of accuracy of the inferred artifact. Confidence factor can be
increased or decreased based on the re-evaluation of sample data for the
artifact.