Unsettled Technology Domains for Pathways to Automotive
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
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.