Replacing fossil-fueled vehicles with battery-electric ones is a risky strategy. It is likely to be limited by the supply of metals critical to battery and solar cell production, and the investment required in decarbonized electricity. Using hydrogen to store renewable energy would greatly reduce efficiency, further increasing the investment required to decarbonize the electricity supply. The lowest technical risk and most economical pathway to decarbonization is reducing private car use. Shorter journeys would be made by walking and cycling – also known as “active travel” – with public transport used for most longer journeys. Realizing this cultural change in transport behavior will first require comprehensive networks for safe and enjoyable active travel, which separate walking and cycling. All locations should connect to either a fully segregated cycleway or traffic calmed roadways with a maximum speed of 30 kph. Active travel investment can save money due to improved public health, eliminate the 11% of carbon emissions caused by short car journeys, and facilitate public transport by empowering people to reach their final destination. Bicycle manufacturing is growing rapidly and further innovations in transport cycles and other lightweight vehicles compatible with an active travel infrastructure will boost this growth. Increased use of public transportation is vital to efficiently use the limited availability of decarbonized electricity. Autonomous vehicles in private use may increase vehicle miles, but autonomous operation within public transportation systems could be transformative. The remaining private cars, buses, and heavy goods vehicles could be electrified more cost effectively using electric road systems. These enable unlimited range and smaller batteries, with the lowest societal cost of any private car-based decarbonization pathway. Although users may pay higher road tax or tolls for the infrastructure, this is easily offset by greatly reduced vehicle costs and improved efficiency. Electrification needs to be brought initially to city bus networks and heavily used transport corridors. Wider use will require standardization and investment at the federal level or continental level. NOTE: SAE EDGE™ Research Reports are intended to identify and illuminate key issues in emerging, but still unsettled, technologies of interest to the mobility industry. The goal of SAE EDGE™ Research Reports is to stimulate discussion and work in the hope of promoting and speeding resolution of identified issues. SAE EDGE™ Research Reports are not intended to resolve the issues they identify or close any topic to further scrutiny. Click here to access the full SAE EDGETM Research Report portfolio. https://doi.org/10.4271/EPR2020014

A narrow focus on electrification and elimination of tailpipe emissions is unlikely to achieve decarbonization objectives. Renewable power generation is unlikely to keep up with increased demand for electricity. A focus on tailpipe emissions ignores the significant particulate pollution that “zero emission” vehicles still cause. It is therefore vital that energy efficiency is improved. Active travel is the key to green economic growth, clean cities, and unlocking the energy saving potential of public transport. The Challenges of Vehicle Decarbonization reviews the urgent need to prioritize active travel infrastructure, create compelling mass-market cycling options, and switch to hybrid powertrains and catenary electrification for long-haul heavy trucks. The report also warns of the potential increase in miles travelled with the advent of personal automated vehicles as well as the pitfalls of fossil-fuel derived hydrogen power. Click here to access the full SAE EDGETM Research Report portfolio. https://doi.org/10.4271/EPR2022SE1

The importance of decarbonizing mobility to slow climate change is already a common goal worldwide. However, there is a lack of alignment on which technological routes to take. While the electrification of mobility assumes dominance in some markets, it is essential to consider specificities of each region so that different applications of transport modes can be concretely evaluated. Decarbonization Routes for Global Road Mobility and Regional Challenges discusses regional approaches, such as those from Brazil and India, that can offer more representative participation in global decarbonization processes. These routes leverage these countries’ domestic talent and regional potential instead of simply copying the solutions coming from developed countries. Biofuels, biomass, and green hydrogen can be very effective ways of reducing global warming for these countries and others with similar economic characteristics, bringing more opportunities for market development and competitive advantages for various economic sectors. Click here to access the full SAE EDGETM Research Report portfolio. https://doi.org/10.4271/EPR2023025

With the current state of automotive electrification, predicting which electrification pathway is likely to be the most economical over a 10- to 30-year outlook is wrought with uncertainty. The development of a range of technologies should continue, including statically charged battery electric vehicles (BEVs), fuel cell electric vehicles (FCEVs), plug-in hybrid electric vehicles (PHEVs), and EVs designed for a combination of plug-in and electric road system (ERS) supply. The most significant uncertainties are for the costs related to hydrogen supply, electrical supply, and battery life. This greatly is dependent on electrolyzers, fuel-cell costs, life spans and efficiencies, distribution and storage, and the price of renewable electricity. Green hydrogen will also be required as an industrial feedstock for difficult-to-decarbonize areas such as aviation and steel production, and for seasonal energy buffering in the grid. For ERSs, it is critical to understand how battery life will be affected by frequent cycling and the extent to which battery technology from hybrid vehicles can be applied. Unsettled Issues in Electrical Demand for Automotive Electrification Pathways dives into the most critical issues the mobility industry is facing. Click here to access the full SAE EDGETM Research Report portfolio. https://doi.org/10.4271/EPR2021004

Sustainable first/last/only-mile (FLO-mile) transport is the key to sustainable travel. It could directly replace private car use for short urban journeys, which account for 1% of global greenhouse gas emissions. More importantly, it could enable public transport to be used for longer journeys, which account for 6% of emissions. Active travel, such as walking and cycling, has the lowest emissions and provides huge economic benefits that pay for the required infrastructure many times over. Unsettled Issues Regarding First- and Last-Mile Transport discusses the mass switch to more sustainable modes of transport and how to increase their perceived value to users. It also covers the prioritization of publicly owned cycles over rideshare options due to the latter’s higher lifecycle emissions, including manufacture, redistribution, and service operations and station construction. Click here to access the full SAE EDGETM Research Report portfolio. https://doi.org/10.4271/EPR2021024

While platooning has the potential to reduce energy consumption of commercial vehicles while improving safety, both advantages are currently difficult to quantify due to insufficient data and the wide range of variables affecting models. Platooning will significantly reduce the use of energy when compared to trucks driven alone, or at a safe distance for a driver without any automated assistance. However, drivers typically drive closer to each other than recommended to achieve drafting efficiencies, which may shift the benefit of automated platooning to safety gains. More data will be needed to conclusively demonstrate these gains. Unsettled Issues in Commercial Vehicle Platooning discusses the technologies needed to enable close platooning, including brake system condition monitoring, vehicle-to-vehicle communication, and concrete infrastructure assessment. The report also looks at driver acceptance of platooning technology from a safety and job security perspective. Click here to access the full SAE EDGETM Research Report portfolio. https://doi.org/10.4271/EPR2021027

To achieve decarbonization through means such as energy-efficient vehicles, active travel, and electrified road freight, solutions must reduce upstream demands on supply chains. However, even taking such a path, the energy transition will massively increase demand for raw materials such as cobalt, nickel, platinum group metals, and rare earth elements. Many of the metals can be largely substituted if required, so they are not truly critical to decarbonization. Critical Metals, Sourcing, and Long Supply Chains: Constraints on Transport Decarbonization discusses how lithium, silver, and copper are much more difficult to replace, and the energy transition is highly likely to depend on them. Greatly increased and more geographically dispersed investments in mineral extraction are vital. Governments must support this by giving investors clear signals about the rate of the transition, geological survey data, accelerated permits, and government backed finance. Public support for sustainable mining should be gained by raising awareness that mineral extraction is critical to combating climate change. Click here to access the full SAE EDGETM Research Report portfolio. https://doi.org/10.4271/EPR2022SE2

Electric road systems (ERS) enable dynamic charging—the most energy efficient and economical way to decarbonize road vehicles. ERS draw electrical power directly from the grid and enable vehicles with small batteries to operate without the need to stop for charging. The three main technologies (i.e., overhead catenary lines, road-bound conductive tracks, and inductive wireless systems in the road surface) are all technically proven; however, no highway system has been commercialized. Electric Road Systems for Dynamic Charging discusses the technical and economic advantages of dynamic charging and questions the current investment in battery-powered and hydrogen-fueled vehicles. Click here to access the full SAE EDGETM Research Report portfolio. https://doi.org/10.4271/EPR2022007

Variable renewable energy (VRE), such as photovoltaic solar and wind turbines, will require new approaches to buffering energy within the grid. This must include significant ancillary services and longer duration storage to buffer seasonal variations in supply and demand. Such services may be economically provided by leveraging the battery resources of electric vehicles (EVs) for frequency response and energy storage for durations of up to a few hours, together with baseload and dispatchable power for longer duration buffering. Impact of Electric Vehicle Charging on Grid Energy Buffering discusses the unsettled issues and requirements needed to realize the potential of EV batteries for demand response and grid services, such as improved battery management, control strategies, and enhanced cybersecurity. Hybrid and fuel cell EVs have significant potential to act as “peakers” for longer duration buffering, and this approach has the potential to provide all the long-term energy buffering required by a VRE-intensive grid. Click here to access the full SAE EDGETM Research Report portfolio. https://doi.org/10.4271/EPR2022022

The world is on a “take-make-waste,” linear-growth economic trajectory where products are bought, used, and then discarded in direct progression with little to no consideration for recycling or reuse. This unsustainable path now requires an urgent call to action for all sectors in the global society: circularity is a must to restore the health of the planet and people. However, carbon-rich textile waste could potentially become a next-generation feedstock, and the mobility sector has the capacity to mobilize ecologically minded designs, supply chains, financing mechanisms, consumer education, cross-sector activation, and more to capitalize on this “new source of carbon.” Activating textile circularity will be one of the biggest business opportunities to drive top- and bottom-line growth for the mobility industry. Textile Circularity and the Sustainability Model of New Mobility provides context and insights on why textiles—a term that not only includes plant-based and animal-based fibers, but plastics as well—are contributing to overflowing landfills, polluted waterways, compromised access to clean water, loss of biodiversity and deforestation, and more. Additionally, it gives an overview of the current state of textile circularity, notable policy and regulatory trends, and how to leverage capabilities of the mobility sector, especially in decarbonization. Click here to access the full SAE EDGETM Research Report portfolio. https://doi.org/10.4271/EPR2024006