The concept of sustainable transportation is intricately linked with the development of sustainable transport modes, infrastructures, and operations. Three major dimensions are considered:
- Environment. A reduction of the environmental impacts of transportation is a likely strategy for sustainability. Transportation contributes to harmful emissions, noise, and climate change. About 15% of the total greenhouse gases and 22% of the CO2 emissions are attributed to transportation. However, as vehicles are becoming more environmentally efficient, the global fleet of vehicles is increasing as well. An improvement of the footprint of transportation, especially the impacts of infrastructure construction and maintenance, is also a strategic goal to achieve. Transportation systems are also waste generators (vehicles, parts, packaging, etc.) that must be reduced, reused, and recycled.
- Economy. Transportation is a factor in economic growth, development, and employment. It requires materials for modes and infrastructure and energy for operations, which can be used more efficiently. Transportation should also have a fair pricing strategy, meaning that users bear the full costs (direct and indirect) of their usage of the transport system. A transport system where competition is fair and open is likely to promote modal choice and efficiency. In a system where transport is a public or private monopoly, price distortions and misallocations of capital can be created, which in the long run are likely to render the system unsustainable.
- Society. Sustainable transportation should benefit society, and it should be safe, not impair human health, and should minimize disturbance in communities. Access and equity are also two important principles as transportation should promote access to goods and services for as many people as possible.
Sustainable transportation fits within the sustainable development goals (SDG). Some SDGs are core to sustainable transportation, such as:
- (3) Health and wellbeing. Ensuring transportation safety and the provision of opportunities through improved mobility.
- (9) Industry and infrastructures. Supply chains and the mobility of passengers and freight.
- (11) Sustainable cities. Urban mobility and logistics.
Other SDGs are more secondary to sustainable transportation, including (7) energy systems, (8) work and economic growth, (12) consumption and production, (13) climate change, (14) water ecosystems, and (15) land ecosystems. The matter is often that reconciling all these goals, which individually appear logical and straightforward, may lead to unsustainable transportation systems because they are too costly, inflexible, and regulated.