This study examines the current operational and economic performance of a sample of companies that operate private fleets and establishes a present-day baseline of transport productivity and efficiency. It also estimates how transportation performance and environmental impact would likely change if the existing federal limitations were to be lifted, resulting in greater maximum gross vehicle weight (GVW) limits and the use of long combination vehicles (LCVs). The study benchmarked the current transportation efficiency of a sample of companies operating private fleets identified in concert with National Private Truck Council (NPTC). The parameters that were used to define efficiency focused on over-the-road operating costs, cargo transported (both by mass and volume), and miles traveled. It includes measures of fuel use, emission output and truck trips required for the companies’ annual transport tasks. The study investigates the change in efficiency under the following scenarios: (1) increased GVW of tractor and 53-ft. semitrailer, and (2) increased cubic capacity using LCVs (specifically, two 53-ft. trailers—“turnpike doubles”) with GVW tied to the bridge formula. The principal findings of the study are as follows: 1. Increases in weight and length would have a direct beneficial effect on the challenges facing American businesses. 2. Large numbers of companies can benefit from increased tractor-trailer weight and length. 3. Companies report significant potential benefits from tractor-trailer weight and length increases. 4. Increasing the weight or length of vehicles also provides benefits for the environment and national fuel supply through reduced energy consumption.