Opportunistic Driving: a Critical Design Space for Reducing Fuel Consumption of Timely Long-Haul Truck Transportation

We study the problem of minimizing fuel consumption of a long-haul truck traveling across national highway under a deadline constraint. We consider a practical setting where the truck traversing a road segment is subject to variable speed ranges due to time-varying traffic conditions. The consideration of variable speed ranges not only differentiates our study from existing ones, but it also allows us to leverage on opportunistic driving to improve fuel efficiency. The idea is for the truck to opportunistically wait (e.g., at highway rest areas) for benign traffic conditions, to traverse road segments at favorable speeds for saving fuel. We observe that the traffic condition and thus the speed range are mostly stationary within certain parts of the day, and we term them as phases. We then propose an efficient phase-based dual-subgradient heuristic which can optimize opportunistic driving to reduce fuel consumption. Simulations based on real-world traces over the US national highway system show that our heuristic significantly saves fuel as compared to several conceivable baselines, where a large part of the fuel reduction is contributed by opportunistic driving.