Freight shipments are increasing around the world as a result of globalization, rising incomes, and shifting patterns of production and consumption. These shipments are a major source of air pollution and greenhouse gas (GHG) emissions. In the U.S., the transport sector accounts for about 28% of GHG emissions, and trucks account for a disproportionate share within the transport sector. California, one of the largest U.S. foreign trade hubs, has been at the forefront of reducing the impacts of freight. Through a series of regulations, subsidies from the state’s cap and trade program, and state funded demonstration programs, California is seeking to accelerate the adoption of zero emission (ZE) and near zero emission (NZE) trucks. A major target is the short-haul trucking sector.

A team of researchers from NCST partner institutions has recently completed a report on the potential for using battery electric heavy-duty trucks to help solve the problem of emissions from freight-related transport. This team includes Genevieve Giuliano, Maged Dessouky, Sue Dexter, Jiawen Fang, and Shichun Hu from USC; Seiji Steimetz and Thomas O’Brien from CSULB; and Lewis Fulton and Marshall Miller from UC Davis. The research project, “Developing Markets for Zero Emission Vehicles in Short Haul Goods Movement,” focused on heavy-duty trucks (HDTs) and the consequences of adopting zero-emission or near-zero-emission vehicles for drayage services, which is the transportation of short-haul goods in the logistics process. This research considers the benefits of battery electric HDTs-- the only zero emission HDTs commercially available -- and their potential use in freight operations, economic impacts, and environmental benefits. The report presents research findings and recommendations for public planning and implementation.

The researchers first considered the impacts of zero or near-zero-emission HDTs compared to conventional diesel HDTs on freight operations through the development of a simulation model using drayage trip data. The research considered three vehicle technologies (diesel, natural gas hybrid, and battery electric) for three target years: 2020, 2025, and 2030. An all-diesel fleet served as the baseline case. The simulation model then estimated the number of trucks required to serve all the demand and incrementally introduced battery electric trucks (BEHDTs) in subsequent model runs. The results indicated that in 2020 the maximum possible share of service operated by BEHDTs is 75%, and it would require a near doubling of the size of the fleet due to the limited range and charging times of BEHDTs in 2020. However, with expected improvements in range and charging times, BEHDTs could operate almost all service in 2025 and 2030; and, by 2030, the fleet size would increase by only 20%.

To gather an industry perspective, Giuliano and her team at USC conducted two rounds of interviews and a survey with industry and drayage professionals. These surveys helped to assess the willingness of transportation professionals to use ZEHDTs, what their perspectives of the costs of implementation were, and which incentives would make the application of these vehicles more acceptable to the industry. Findings suggest that ZEHDTs currently have a limited application in the short-haul market. However, hybrid near-zero vehicles have more potential in the short-term. It was also noted that the implementation of these technologies will rely heavily on the development of charging stations and battery technology in the near future.

The USC and UCD teams used the simulation model results to compare the costs and emissions reductions for natural gas hybrid and BEHDTs relative to diesel, again for 2020, 2025, and 2030. They found that the hybrid alternative is the least cost alternative for all emissions and all target years. This is due to the lower operating costs of hybrids and lower emissions relative to diesel. At the same time, the hybrid alternative does not require additional vehicles, and therefore has much lower capital costs than the BEHDT alternatives. The researchers noted that their results illustrate the contrast between possible policy objectives. If reducing emissions is the most important objective, ZEHDTs meet that objective, but at very high cost relative to other alternatives.

In a related component of the research, CSULB researchers led by Seiji Steimetz conducted a data-driven experiment designed to estimate how factors could affect electric trucks’ ability to penetrate the short-haul trucking market. The CSULB team of researchers deployed an online survey that asked trucking industry decision makers to choose between conventional diesel and electric trucks after comparing their purchase prices, fuel costs, maintenance costs, ranges, refueling/recharging times, the availability of charging stations, and access to high-occupancy lanes. The team found evidence that policies governing pricing, operating costs, time-savings, and other factors may indeed be effective in incentivizing the adoption of electric trucks. However, these findings are best viewed as preliminary, considering that they are based on a small sample of respondents to a stated preference survey.

The interviews and survey responses suggested that ZEHDTs need attributes similar to conventional diesel vehicles if they are to be attractive in the marketplace. Important factors include purchase price, availability and accessibility of charging stations, and vehicle features like range and charging time. The research report includes recommendations such as increasing the number of public charging stations available for electric vehicles, considering hybrid technology for the medium term, and continuing to invest in battery and other zero emission technology development. The report also recommends that there be an expansion of state and local policy to “…take into account the full impact of ZEHDTs and freight operations and costs.” The report concludes that there is promise for significant ZE market share by 2030. Achieving that share will require public investment in charging infrastructure and a broad set of incentives to promote ZE use.