Impact of Designated Secure Rest Facilities on Single-Lane Truck-Dispatching Productivity

This paper develops an approach for analyzing how restricting rest (sleep) locations for long-haul truckers may affect operational productivity, given hours-of-service regulations. Productivity is measured by the minimum number of unique drivers required to execute a set of load requests feasibly over a known planning horizon. When drivers may stop for rest at any location, they should be able to maximize utilization under regulated driving hours. When drivers may stop for rest only at certain discrete locations, drivers may suffer decreased utilization. The framework and results developed in this paper should be especially useful in the analysis of truck transportation of security-sensitive commodities, such as food products and hazardous materials, for which there exists strong external pressure to ensure that drivers rest only in secure locations to reduce risks of tampering. The analysis considers the simplest case, in which all loads to be transported move along a single lane. The paper presents an optimal tree search algorithm for determining the minimum number of drivers required to cover a set of loads given a set of allowed rest locations. Because the optimal approach is often computationally burdensome, the paper also presents and analyzes a set of simple heuristics for determining feasible load-to-driver assignments that can augment the search for the true minimum. Analysis of a sample data set demonstrates the approach and indicates that for lanes of realistic length, the productivity impact of restricting rest to a small number of discrete locations is likely to be small.