Satisfying the demand for goods requires the movement of commercial and private vehicles, which are responsible for multiple negative impacts including noise, emissions, and traffic congestion. While efficiency is crucial for sustainable and profitable freight transportation, operations are typically inefficient with respect to emissions and social impacts. The reasons for such inefficiency are diverse, including the need for several attempts to complete a delivery and the under usage of vehicle capacity. The arrival of zero-emission and near-zero-emission medium- and heavy-duty vehicles may reduce (tailpipe) emissions. Multiple government agencies have supported the development and promotion of cleaner vehicles through strategies such as economic incentives to support purchases and disincentives to using internal combustion engine vehicles. However, small- and mediumsized companies face challenges in adopting cleaner vehicles, either because of high purchase costs or because the volume of their operations may not justify the expense. To address this issue, this work evaluates cooperative strategies between noncompeting companies that would exploit economies of scale through the sharing of vehicle capacities in joint routing. The work develops a decision support tool named Cargo Aggregator Beta 1.0, which provides companies willing to cooperate with an efficient joint route to pick-up and deliver cargo from different origins and destinations. The tool, based on an extension of the vehicle routing problem, allows users to consider different vehicle capacities, decide on charging and/or refueling points, consider multiple depots, and guarantee the completion of all deliveries in a general time window. The tool can be used to better understand the impact of sustainability policies that would limit the amount of pollutant emissions generated, or policies that seek to restrict fleet composition. Numerical analyses using study cases in California show the potential benefits of implementing these collaborations in reducing both costs and emissions.