NREL has conducted a variety of studies to assess the fuel-saving potential of truck platooning and pinpoint areas in need of future research.
Platooning reduces aerodynamic drag by grouping vehicles together and safely decreasing the distance between them via electronic coupling, which allows multiple vehicles to accelerate or brake simultaneously.
NREL conducted a temporal and geospatial analysis using 210 million miles of real-world telematics data from more than 57,000 Volvo Trucks to estimate the fraction of miles traveled by Class 8 trucks in the United States that are suitable to platooning. Results of this large-scale study indicate that 63% of the total miles driven occur at speeds amenable to platooning. When also considering the availability of nearby partner vehicles, this number decreases somewhat to 55.7%. Refer to the conference paperfor details.
Results of this study compliment an earlier study in which NREL tapped into the Fleet DNA repository of commercial fleet vehicle operating data to estimate the fraction of total miles driven by Class 7 and Class 8 freight trucks that are suitable for platooning. NREL analyzed 3 million miles of high-resolution data and found that about 65% of the total miles driven by such trucks could be driven in platoon formation—leading to a 4% reduction in total truck fuel consumption and significant cost savings for truck operators. Refer to the conference paper for details.
NREL partnered with National Research Council Canada, Transport Canada, Lawrence Berkeley National Laboratory, Volvo, and others in a comprehensive assessment of the fuel-saving potential of cooperative vehicle automation systems in three-truck platoons. Results demonstrated a wide range of fuel savings—with the lead vehicle saving up to 10% at the closest separation distance of 4 meters, the middle vehicle saving up to 17% at 4 meters, and the trailing vehicle saving up to 13% at 10–20 meters.
The team also assessed the impact of speed variations, road curvature, other vehicles cutting in/out of the platoon, the use of mismatched vehicles (i.e., trucks with standard and aerodynamic trailers in the same platoon), and the presence of a passenger vehicle traveling in front of the platoon. Refer to the conference paper for details.
In a previous study, NREL conducted track evaluations of three SmartWay tractors—two platooned tractors and one control tractor at varying steady-state speeds, following distances, and gross vehicle weights. While platooning improved fuel economy at all speeds, travel at 55 mph resulted in the best overall miles per gallon. The lead truck demonstrated fuel savings up to 5.3% while the trailing truck saved up to 9.7%. NREL found that several conditions impact the savings attainable, including ambient temperature, distance between lead and trailing truck, and payload weight. Refer to the conference paper for details.
NREL analyzed the results of several independent truck platooning projects conducted by various organizations as well as the results of wind tunnel tests and computational fluid dynamics simulations. NREL found broad consensus among results and identified areas in need of additional research—close formation and longer-distance effects, aerodynamic packages optimized for platooning, measurement of platoon system performance in various traffic conditions, impact of vehicle lateral offsets, and characterization of the national potential for platooning based on fleet operational characteristics. Refer to the report for details.
The following documents provide more information about NREL's truck platooning evaluations.
Technical Reports and Conference Papers
- Impact of Lateral Alignment on the Energy Savings of a Truck Platoon
- Impact of Mixed Traffic on the Energy Savings of a Truck Platoon
- Impact to Cooling Airflow from Truck Platooning
- Exploring Telematics Big Data for Truck Platooning Opportunities
- Influences on Energy Savings of Heavy Trucks Using Cooperative Adaptive Cruise Control
- Correlations of Platooning Track Test and Wind Tunnel Data
- Potentials for Platooning in U.S. Highway Freight Transport
- Effect of Platooning on Fuel Consumption of Class 8 Vehicles over a Range of Speeds, Following Distances, and Mass