To make transportation more efficient, we need to move more goods and passengers while emitting fewer harmful GHGs. Some efficiency improvements, such as reducing vehicle miles traveled (VMT) and the carbon footprint of freight and cargo handling, can create economic benefits across the transportation sector.
While expediting near-term decarbonization, increasing mobility and transit options can also provide important health and community benefits. Prioritizing clean and affordable transportation options is a common tenet of national environmental justice efforts. Scaling up investments in efficient mobility, zero-carbon public transit, affordable access to zero- and low-carbon vehicles, and planning for communities to promote safe walking and biking can reduce carbon emissions, improve air quality, and result in better health and more low-carbon public transit options in disadvantaged communities.
In addition, technologies that increase fuel economy, reduce the weight of vehicles and equipment, and provide equitable transportation options across all communities will further amplify the carbon reductions achieved through electrification and the use of low-GHG liquid fuels.
Land Use and Permitting
Local policy makers must develop transportation systems that balance the needs of all users: freight carriers, motorists, transit riders, bicyclists, and pedestrians. But land use and permitting can be a significant barrier to the development of efficient, balanced, multimodal transportation networks. Planners must consider existing housing and development policies and zoning requirements when considering major investments in transit or improvements to freight facilities. Policies should link housing, land use, and mobility and work to streamline the permitting processes for projects that show net benefits in housing and environmental attributes, including air quality improvements and employment opportunities. They should also prioritize investments that provide direct benefit to underserved and historically disadvantaged populations.
In the U.S., transit ridership has grown by more than 20 percent in the last decade. However, public perception of transit as unreliable, inefficient, and inconvenient has slowed its rate of market adoption. Transit investment has lagged in low-income and historically disadvantaged communities, resulting in transit deserts in areas with limited economic opportunity and poor air quality. Transit demand has also been hampered by low gas prices that do not reflect the fuel’s green premium, as well as by the rise of transportation network companies (TNCs) like Uber and Lyft. Policies that increase investment in public transit and result in more reliability and lower costs can work to reduce these market barriers.
Shifting public expectations of freight delivery systems also impede the development of more efficient mobility. The race towards ever-faster shipping is driving companies like Amazon, UPS, and FedEx to increase delivery trips. Instant (and often free) shipping encourages consumers to make multiple small purchases which can increase vehicle miles traveled (VMT) and reduce efficiency. Policies that encourage reductions in freight VMT and require adoption of zero-emission freight equipment can work to reduce the carbon footprint of this new reality of instant delivery.
Large upfront capital costs are a huge market barrier to the purchase of zero-emission freight equipment at transportation hubs such as ports, distribution centers, airports, and rail yards. Despite potential long-term savings due to reduced operating and maintenance costs, zero-emission equipment remains out of reach for most transit and freight operators. Procurement policies that require federal and state purchases of advanced technology equipment can drive down production costs through economies of scale. Fiscal incentives can further reduce the green premium of zero-emission equipment and help encourage market penetration.
Technology Innovation Examples
One of the best ways to reduce carbon emissions from transportation is to make all vehicles—cars, trucks, planes, trains, and ships—lighter. In a typical light-duty car, every 10 percent reduction in weight increases fuel efficiency by 6–8 percent, and a 30 percent weight reduction improves efficiency by up to 20-25 percent.
The use of strong, lightweight materials like carbon-fiber–reinforced plastics and metals such as aluminum or magnesium present tremendous opportunities for vehicle-weight reduction. However, these materials are currently too expensive to manufacture, and cost-effective technologies for joining them together into lightweight structures do not yet exist in many cases. To see dramatic reductions in GHG emissions, we need to develop transformational new lightweight materials, inexpensive manufacturing processes, and new material-joining processes.