Repeatability of on-road routes and a comparison of on-road routes to the federal test procedure

West Virginia University has developed a Mobile Emissions Measurement System that recorded vehicle, engine, and exhaust behavior during in-use testing. This system obtained data from numerous vehicles over specified on-road routes. A study was conducted on on-road route repeatability. A methodology for finding repeatability had to be established, and factors influencing repeatability were identified. It was found that routes and drivers significantly influenced repeatability, and that further study of a larger sample group needs to be conducted before specific conclusions could be drawn about the influences of the vehicle on repeatability.; A further study was conducted on how well the on-road routes compare to the federal emissions test. Engine behavior for on road testing was binned and compared to the federal certification test. It was found that routes that contained substantial portions of urban traffic were more representative of the federal test procedure than routes with mostly freeway driving.