An emissions and energy comparison between a simulated Automated Highway System and current traffic conditions

An evaluation has been carried out in estimating the emissions and energy use (i.e., fuel consumption) associated with an Automated Highway System (AHS) using advanced simulation modeling tools. A detailed AHS microsimulation has been combined with a comprehensive modal emissions and energy consumption model to predict emissions and energy use for a modeled highway. The resulting AHS emissions and fuel consumption are compared to non-automated traffic at different levels of congestion, as well as idealized traffic flow. The results of this preliminary evaluation have shown that an AHS has slightly lower average fuel consumption than a nonautomated highway operating at free-flow, and much lower average fuel consumption than a non-automated highway operating under congested conditions, because of its smoother traffic flow. Further, an AHS operating at 60 mph has substantially lower emissions per vehicle-mile traveled than non-automated traffic at the same average speed, again because of its smoother traffic flow. Vehicles that platoon in an AHS can expect an additional 5 - 15% fuel savings and emission reduction due to the aerodynamic drafting effect, which is dependent on the intra-platoon vehicle spacings.