- Truckers are not using tail fairings (a key component of the EPA/NHTSA standards for trailers)—although they are embracing the use of skirts and automatic tire inflation devices.
- There was no significant difference in the use of skirts or ATI devices with separate tractor and trailer owners compared to with integrated ownership (i.e., no evidence that there is a split incentive problem).
- There was significantly lower incidence of use of skirts and ATI devices for trailers with day cabs.
- There was significantly lower incidence of use of skirts on US 50 (near Bay Bridge) versus use on I-81 and I-95.
Several federal agencies claim the existence of an energy paradox in competitive markets in their benefit-cost analyses: firms fail to use energy-saving equipment that on net would reduce their costs. Such findings appear incompatible with neoclassical views that private firms in competitive markets will seek to minimize costs. EPA and NHTSA (2016) justify their findings in part by claiming that owners of trailers pulled by others underinvest in energy-saving equipment because the trailer owners incur the costs of such investments while tractor owners get the benefits. We collected roadside data over three summers and model use of energy-saving equipment on trailers. We find associations consistent with cost-reducing behavior in the use of energy efficiency devices, such as skirts and automatic tire inflation devices, but no evidence that different ownership of tractors and trailers is associated with reduced use of energy-saving equipment on trailers. We recommend that EPA and NHTSA assess the in-use cost-effectiveness of such equipment and rigorously review the empirical basis for claims of market failures in competitive markets before claiming significant private economic gains in rulemakings.