In this guide, we outline the basics of sustainable transport.
We explain what sustainable transport is, the different types and examples of sustainable transport, and other important considerations.
Summary – Sustainable Transport
Sustainable transport generally involves improving the impact transport factors have on the environment, resources, the economy, and society, both in the short term and long term.
There’s also practical, logistical and technical considerations to take into account
Specifically when talking about environmental and resources sustainability, sustainable transport might help address issues such as the finite nature of fossil fuels, air pollution and carbon emissions
Putting impact aside, the three main transport factors to look at might be the type/mode of transport, how that type of transport functions and works, and the infrastructure required
The three main types of transport might include land, water and air based transport
How transport works and functions includes looking at the energy/fuel source, design and systems used, features, performance, and other factors
Infrastructure includes looking at the current infrastructure in place, and looking at what infrastructure would be required in the future, as well as what a new build infrastructure transition would look like
There’s a number of ways to measure environmental, economic and social impact of sustainable transport
There’s a number of solutions that have been suggested or implemented in sustainable transport, with each having different tradeoffs
There’s a number of challenges and limitations in implementing sustainable transport
It’s important to pay attention to the trends in the transport industry to see how different solutions are having an impact on overall metrics and issues
There’s a number of ways to measure different indicators and issues in sustainable transport
What Is Sustainable Transport?
Sustainable transport is sometimes called green transport, and is usually what people are referring to when they refer to transport that takes into account it’s impact on the environment, and also resources.
One example of environmental impact could be the level of carbon emissions from the form of transport in question.
One example of impact on resources could be whether the form of transport uses no fuel, uses a fossil fuel based fuel, or whether it’s fuel comes from renewable sources (there’s questions over how much oil we have left to use for the future). So, essentially, the source of energy the fuel comes from
In reality though, environmental footprint is not the only consideration.
There’s economic, social, and practical and technical considerations that have to be taken into account too.
Just two examples are that:
– sustainable forms of car transport would have to be affordable if they are to be scaled up and mass produced for the population
– and, they would have to have a basic level of driving performance to ensure the average person can perform the driving activities they need for work and personal use.
So, a truly sustainable mode of transport would consider more than just the environmental aspect of sustainability.
It considers the mode or type of transport itself (or some type of factor that creates an impact on something else – like an activity, a policy or regulation, and so on), environmental impact, social impact, economic impact, and practical, logistical and technical considerations.
The Factors Involved In Looking At Transport
Putting aside the different types of impact and practical and technical considerations, the three main factors to assess when looking at transport might include:
1. The mode/type of transport
2. How the type of transport functions and works – the energy source the transport uses, the systems it uses, the features it has, it’s design, it’s performance, and so on
3. Infrastructure to support the type/mode of transport
Types Of Sustainable Transport (& Examples)
The main types of sustainable transport might be (with examples):
Cycling/Biking (without and with a motor – petroleum or electric)
Petrol Scooters & Mopeds
Electric Scooters & Skateboards
Train (or other types of railway transport)
Private vs Commercial Use Transport (e.g. transport owned by companies, or used for freight and import/export)
Canoe (or other types of water transport with paddles)
Sail Boats (without a motor, or with the ability to function both with and without a motor)
Small Boats (with a motor)
Large Boats & Yachts (with a motor, for personal and commercial use)
How The Type Of Transport Functions & Works
It’s not enough to just look at the type of transport.
How the type of transport functions is equally as important i.e. the system of movement the transport is designed for, the fuel it uses (and the energy source of the fuel), it’s overall design and features, it’s performance, etc.
Looking at just one example in passenger cars, we can see some of the different types of fuels and systems used in cars:
– Petroleum fuel with internal combustion engine (Currently 95% of transport energy comes from petroleum – wikipedia.org)
– Electric vehicle (note that some electric vehicle run on electricity supplied by mainly fossil fuels, and some run on electricity supplied by mainly renewable energy sources like solar and wind)
– Cars that run on fuel other than petroleum based fuel (gasoline or diesel for example), such as natural gas, ethanol, or the latest generation of biofuels (that may have improvements on previous generations of biofuels). The afdc.energy.gov resource in the sources list outlines some alternative fuels. Some vehicles are flexible or dual fuel vehicles
If we take any one of the above cars, we can ask additional questions like:
– Does the car run partially on electricity and partially on another fuel? If so, what is the % balance, and what is the other fuel used?
– If the car runs fully on electricity, what energy source does the electricity come from?
– What features does the vehicle have? Does it have regenerative braking that help reduce the transport footprint? What impact does the weight of the car have on fuel consumption efficiency? In the case of electric vehicles, the capabilities of the battery can have a significant impact on sustainability.
– How many people can travel in the vehicles at once? The more people, the more it cuts down on the transport footprint
These points are all related to energy source, design, features, performance, effectiveness, efficiency (such as fuel efficiency), and generally how the vehicle works and functions.
There may not be one perfect solution as all modes of transport may have pros and cons, and tradeoffs to consider. As just one example:
– Electric vehicles may have issues to do with what energy source the electricity comes from, and also to do with electric vehicle battery disposal and waste management/recycling and re-use
Infrastructure To Support The Transport
In addition to the type of transport itself, all transport needs infrastructure.
– Conventional cars need roads and parking lots, and also refuelling stations
– Trains and trams need railway tracks
– Hydrogen fuel cell vehicles need infrastructure to transport hydrogen, and hydrogen refilling stations
Consideration should be given to:
– The infrastructure already in place
– What would be required to build new infrastructure, or transition to new infrastructure
Potential Environmental Impact & Resource Impact Of Transport
Some general guides on the impact of transport on the environment are:
When looking at environmental and resource usage impact, it’s important to look at:
The whole lifecycle of the mode of transport – manufacture, operation, and end of life
The transport type directly, but also at indirect factors such as repair, cleaning, refuelling stations, transport of fuel, and so on, to get an accurate view of the real footprint
Some specific potential environmental impacts might include:
Greenhouse Gas Emissions
– according to some reports, transport is responsible for 14% of all global greenhouse gases compared to other industries
– [about three quarters of global greenhouse emissions in the transport sector come from road vehicles] (wikipedia.org)
– US cities on average emit more greenhouse gases than any other countries’ cities per person, per year (wikipedia.org)
Read more about transport and air pollution in this guide
In terms of resource use, the issues might include:
– Using non renewable fossil fuel based fuel for cars, trucks, planes, and other types of transport
– Land use is another issues (think about the amount of land used for roads, parking space, and transport infrastructure – could land be used in a more effective and better way?)
When you consider the amount of the world’s energy that transport uses, it makes sense that that energy (mainly in the form of fuel or power) should be sustainable to use.
Potential Impact Of Transport On The Economy
Advanced transport technology and the development of personal passenger vehicles are key factors that have allowed economies to grow, and quality of life to be increased.
Aside from this, there’s the economic cost of transport, and supply and demand factors to consider.
Each new form of transport needs to have a thorough economic cost/benefit analysis done to see if it’s economically viable.
Potential Impact Of Transport On Society & People
Some of the potential impacts of transport on people might include:
– Better mobility and increasing quality of life
– The health impact of factors like air pollution
– Some say it contributes to obesity where people drive instead of walking and cycling some places
– The health impact of transport accidents
– Miscellaneous impacts like it’s impact on city planning, and addressing issues like congested traffic and congested transport systems
Solutions In Sustainable Transport
Some of the general solutions in sustainable transport might include:
– Walking and biking more (but note this uses human energy, and some bikes have motors)
– Using transport with greener fuel that is based on renewable resources
– Fuel efficiency improvements (needing less fuel per mile driven)
– Reducing total number of miles driven per year on a global scale
– Lowering the per capita negative transport footprint
Other solutions can include:
– [Clean fuels and vehicles, cleaner transport infrastructure, access restrictions, integrated pricing strategies, tools and incentives such as financial benefits or taxes, collective passenger transport, better information, less car intensive lifestyles, soft measures, sustainable transport management, sustainable freight transport] (wikipedia.org)
– [Advances like self driving vehicles, dealing with mitigation vs adaptation issues, managing transport demand, improving transport supply, and various decarbonization efforts] (transportgeography.org)
– Sustainable transport solutions have their greatest effect in cities (wikipedia.org)
The problems these solutions might help address are related to the impact based problems.
Limitations & Challenges With More Sustainable Transport
There can be many limitations and challenges in implementing more sustainable transport.
Some of those include, but aren’t limited to:
– Making newer more sustainable forms of transport cost effective, economically competitive, and affordable
– How adaptable to change newer sustainable transport is
– A city being locked into certain aspects of it’s city design and location
– The time lag challenge in investing in transport technology and infrastructure, and transitioning to infrastructure for more sustainable transport
– Scaling production to meet demand for sustainable transport
– Technical and practical issues to do with mobility, performance and effectiveness of newer and more sustainable transport types
Transportgeography.org does a good job of listing some other limitations and challenges.
Measurements In Sustainable Transport
Some of the different measurements that might give an indication on the progress of sustainable transport might include:
Carbon emissions per passenger mile
Air pollution emission per passenger mile
Total carbon emissions from transport
Total air pollution from transport
% carbon emissions from transport compared to other industries
% air pollution from transport compared to other industries
Total number of vehicles on the road
Total number of vehicles projected to be on the road by the years 2030, 2050, and further into the future
What Are The Trends With Car Use In The Last Few Decades?
In general, the total number of cars on the road and the total number of miles driven are increasing, but some figures show that some per capita fuel use are decreasing in some areas.
– The number of vehicles and cars in the world right now
– The expected increase in population size
– The total distance all transport is travelling per year, per passenger (takes into account all modes of transport, and total number of passengers in that transport)
– Are any transport methods like car pooling or ride sharing used that help lower the transport footprint?
– Cities to a certain extent are locked into their transport systems and results depending on their location and the layout of their city. Some of this can be changed, and some of it can’t.
5. Rodrigue, J-P et al. (2020) The Geography of Transport Systems, Hofstra University, Department of Global Studies & Geography, Available at https://transportgeography.org/contents/chapter4/transportation-sustainability-decarbonization/