The demand for passenger and commercial transportation increases strongly over the Outlook, with road and air travel doubling in all three scenarios. The growth in final energy required to fuel this increased travel is offset by significant gains in vehicle efficiency, especially in passenger cars, trucks and aviation.
The gains in energy efficiency are partially disguised by a shift away from oil towards the increasing use of electricity and hydrogen in transport. In particular, the conversion process used to produce these energy carriers boosts the total amount of primary energy absorbed by the transport sector. The shift towards electricity and hydrogen is most pronounced in Rapid and Net Zero, where overall primary energy increases by around 25% and 35% respectively by 2050. Primary energy in transport increases by almost 25% in BAU, with slower gains in energy efficiency offset by a smaller shift away from oil.
The growth in primary energy used in transport in all three scenarios stems entirely from the developing world, as increasing prosperity in developing Asia, Africa and Latin America supports greater demand for passenger and freight transportation. Energy use in transport in the developed world is broadly flat.
The use of oil in transport peaks in the mid-to-late 2020s in all three scenarios: the demand for oil for road transport in emerging markets continues to increase until the early 2030s in Rapid and Net Zero, and the late 2030s in BAU, but this is increasingly offset by falls in the developed world.
The share of oil in total final consumption falls from over 90% of transport demand in 2018 to around 80% by 2050 in BAU, 40% in Rapid and just 20% in Net Zero. The main counterpart is the increasing use of electricity, especially in passenger cars and light and medium-duty trucks, along with hydrogen, biofuels and gas. The share of electricity in end energy use in transport increases to between 30% and 40% by 2050 in Rapid and Net Zero.
The outlook for energy use in road transport is dominated by two major trends: increasing electrification and improving vehicle efficiency.
The electrification of the vehicle parc is most pronounced in Rapid and Net Zero, concentrated in two and three wheelers, passenger cars and light and medium-duty trucks. Electric vehicles in Rapid and Net Zero account for around 30% of four-wheeled vehicle kilometres (VKM) travelled on roads in 2035 and between 70-80% in 2050, compared with less than 1% in 2018. The corresponding shares in BAU are a little over 10% in 2035 and around 30% in 2050.
By 2050, electric vehicles account for between 80-85% of the stock of passenger cars in Rapid and Net Zero and 35% in BAU. The corresponding numbers for light and medium-duty trucks are 70-80% and 20%.
The other dominant trend affecting the use of energy in road transport is the increasing levels of vehicle efficiency, especially passenger cars, driven by tightening vehicle emission standards and rising carbon prices which are largely borne by consumers in the form of higher gasoline and diesel prices. In Rapid, the efficiency of a typical new internal combustion engine (ICE) passenger car increases by around 45% over the next 15 years.
Despite the accelerated electrification of passenger cars, the continuing importance of ICE passenger cars for much of the Outlook means that improvements in their efficiency is the main factor limiting the growth of oil used in passenger cars out to 2050.
Vehicle efficiency improvements in Rapid reduce oil use in passenger cars (and hence carbon emissions) by roughly twice as much as electrification out to 2050.
The composition of road transportation across different modes of transport, e.g. private cars, taxis, buses etc, is affected by two significant trends over the Outlook: increasing levels of prosperity and the falling cost of shared-mobility transport services. Both trends have important implications for the pace and extent to which the transport sector is decarbonized.
The increasing levels of prosperity and living standards in emerging economies leads to a shift away from high-occupancy forms of transport (e.g. buses) into passenger cars. This leads to a reduction in average load factors (i.e. average number of passengers per vehicle), putting upward pressure on carbon emissions.
The relative cost of shared mobility services falls as a result of a range of factors, including continuing advances in digital technologies such as improving connectivity and geospatial technologies. In addition, digital advances enable automated driving systems and the emergence of fully autonomous vehicles (AVs) from the early 2030s in Rapid and Net Zero, significantly reducing the cost of shared-mobility services, especially in developed economies where average income levels are higher. The falling relative cost of autonomous shared-mobility services (robotaxis) leads to a shift away from private-owned vehicles as well as buses.
The vast majority of robotaxis are electric in all three scenarios. This reflects the local air quality benefits and lower running costs of electric cars relative to traditional (internal combustion engine). Electric robotaxis provide a significant cost advantage given the intensity of use – up to 9-times greater than private cars by 2050. The growing penetration of robotaxis, combined with their intensity of use, means that by 2035 they account for around 40% of passenger VKM powered by electricity in Rapid and Net Zero and around 20% in BAU. This share declines in the final 10-years or so of the Outlook in Rapid and Net Zero as the share of private ownership of electric cars increases.
The potential for robotaxis to help decarbonize road transportation by increasing the share of passenger car VKM powered by electricity means they are supported by government policies, such as higher road pricing and congestion charges for private vehicles, particularly in Rapid and Net Zero. The importance of robotaxis is also supported in Net Zero by a shift in societal attitudes towards a sharing economy.