The Hierarchy of Sustainable Transportation
While it’s relatively easy to imagine living in today’s world without certain creature comforts, it’s difficult to imagine doing so without cars, airplanes, and other powered modes of transportation. But the truth is, there’s a possible future where the transports that we rely so heavily on today may not be readily available.
The current transportation system in the United States – which is heavily dominated by individual vehicles – is an extremely unsustainable one. Most obvious of sustainability concerns is that fossil-fuel-powered vehicles are responsible for significant carbon dioxide emissions. However, the unsustainability of the current transportation model runs far deeper than just emissions.
To tackle this issue, it’s highly necessary to standardize a hierarchy of sustainable transportation, one which highlights eco-friendly modes of transportation (such as biking) and sheds light on the unsustainability of others (such as flying). Currently, the more sustainable option isn’t always the most convenient. But as the culture shifts towards a greater focus on sustainability, so will the accessibility.
Photo by Thomas Loizeau
An overview of the current transportation system in the U.S.
In the United States, 91.7% of households own at least one car, leaving 8.3% of households without a vehicle. As of 2021, there were 278,063,737 registered passenger vehicles, an average of about 838 vehicles per 1000 people. For comparison, here’s a list of countries by vehicles per person. The United States is notably in the top 10 of this list, along with Canada and New Zealand.
Given the staggering amount of cars in the US, it comes as no surprise that travel by automobile is the most common mode of transportation by far, at least for shorter distances. This immense volume is supported by policies that favor cars and infrastructure that includes a complex network of highways, freeways, city roads, and more.
But cars are not the only way that people get around the United States; passenger travel occurs on foot, by bike, by motorcycle, and by way of public transportation such as buses, trains, and trams. But if you’ve ever paid a visit to Canada or a European country, you’ll likely have found their public transportation systems to be more convenient and well-used than those in the US. Not to mention the safer, better-established infrastructure for biking in European countries such as Holland.
Why public transit use is lower in the US than it is in Western Europe and Canada is a complex issue, one which you can read more about here (esp. page 28). It mostly comes down to factors such as population density and lack of proper infrastructure. True, there are a few places in the US that have popular transportation systems, namely New York and Washington DC, but these are outliers rather than the norm.
For longer distances, all of the same modes of transportation are, to some extent, possible. But most people won’t be biking across the US unless they have a few months of spare time. More often, long distance travel occurs by car, train (e.g. Amtrak), bus, boat, or airplane. In 2022, airplanes carried 853 million passengers to their destinations.
What is sustainable transportation?
As you’ve likely experienced yourself, it’s far more convenient to travel by car in the US than almost any other form of transportation. Unfortunately, short of traveling by helicopter or airplane, it’s also one of the least sustainable modes of transport.
But what is sustainable transportation exactly? According to the Department of Energy (DOE):
“Sustainable transportation refers to low- and zero-emission, energy-efficient, affordable modes of transport, including electric and alternative-fuel vehicles, as well as domestic fuels.”
The most obvious zero-emissions forms of transportation are the ones that require no fuel or electricity at all. Man-powered movement, such as walking and running, couldn’t be more sustainable. But they’re also not particularly convenient, unless you’re traveling just a few miles or less. Slightly more convenient is biking, but even that has limits beyond traveling around town.
For longer distances and tighter schedules, it’s clear that fuel-powered modes of transportation are a must. While the electrification of passenger vehicles is a key component of sustainable transportation, so is public transit. The latter not only takes up less space on the roads (1 bus has a smaller footprint than 10 cars, for instance), but it cuts emissions and uses less fuel. We’ll take a closer look at the sustainability of different modes of transportation further on.
Why do we need sustainable transportation?
As global warming continues unabated, it’s critical that transportation shifts to a focus on sustainability now and in the coming years. Currently, the transportation industry is responsible for 29% of greenhouse gas emissions, more than any other sector. These GHG emissions are heating up the earth’s atmosphere, driving global warming as we speak.
If that wasn’t enough, transportation still relies primarily on fossil fuels. Even electric vehicles aren’t completely free of fossil fuels, as a large proportion of electricity in the US still comes from the burning of fossil fuels. But fossil fuels are a limited resource, and they will run out eventually.
The benefits of sustainable transportation
Besides reducing the impacts of global warming, sustainable transportation have numerous benefits for individuals as well as society:
Cost savings: you buy less fuel and extend the life of your vehicle, resulting in further cost savings over time from repairs or vehicle replacement.
Less air pollution: traveling more sustainably means less GHG emissions.
Clearer skies: less air pollution means cleaner air, resulting in healthier communities.
Promotes health: besides less air pollution, sustainable transportation (especially biking and walking) promotes physical exercise and overall well being.
Safer transport: public transit is safer than traveling by car, and improvements in bike lane infrastructure would also greatly improve the safety of biking.
Creation of new jobs: investments in sustainable transportation translate to jobs creating EV batteries and designing/building public transit infrastructure.
Energy security: by focusing on sustainable transport and sources of clean energy, we’ll be less reliant on limited (and foreign) sources of fossil fuels.
Fewer harmful chemicals: taking sustainable transport not only reduces the consumption of fossil fuels but also other harmful chemicals such as antifreeze.
Less cars on the road: with less usage, roads last longer and fewer roads have to be built, conserving resources and land as a result.
Less noise pollution: cars, airplanes, and helicopters are noisy; traveling sustainably will make cities and neighborhoods a more pleasant environment to the ear.
The hierarchy of sustainable transportation
It’s clear we need to shift to using more sustainable modes of transportation, but which ones are better than others? Just like we have a hierarchy of waste management, we’ve put together a hierarchy of sustainable transportation that you can turn to when thinking about your next trip or day-to-day commute.
From most sustainable, to least sustainable, here’s the hierarchy of sustainable transportation:
Bike
Walking/running
EV vehicle powered by clean energy
Bus
Train
Motorcycle
Carpooling (2+ persons per vehicle)
EV vehicle powered by fossil fuels
Average passenger vehicle
Passenger airplane
Private airplane
Helicopter
Interested in the statistics behind the hierarchy of sustainable transportation? You can learn more here, here, and here.
Key takeaways from the hierarchy of sustainable transport
Despite the environmental costs associated with producing an e-bike and powering its battery, it’s considered the most sustainable mode of transportation because it results in fewer calories burned than when walking, running, or cycling; and, as you know, the production of food requires energy, land, and resources.
Notably, an electric vehicle is little better than a standard passenger vehicle if it’s powered by electricity from fossil fuels. EVs powered by clean energy, on the other hand, are much more sustainable.
Currently, the more sustainable options aren’t always the most convenient or even the safest. We need improved infrastructure and better policies in place to guide individuals, businesses, and cities in a more sustainable direction. We can already see this happening with government incentives for electric vehicles, but it’s also highly necessary for bike lanes and public transit infrastructure!
Widespread, efficient, and sustainable public transit is possible in the US. Here’s how.
How you can incorporate sustainable travel in your life
Until taking public transit is as convenient as driving a car in terms of cost, time, and accessibility, no one is expecting you to give up driving a car. However, that doesn’t mean you can’t make more sustainable travel choices in your day-to-day life.
It comes down to shifting your perspective and thinking critically about your transportation. Simple ways to make small changes include: finding ways to carpool with friends, family, and co-workers; swapping out the car for a bike whenever possible; combining short trips to cut down on car usage; traveling locally instead of flying abroad for a vacation.
How do you find ways to make more sustainable transport choices? What would you like to see change in your town or city to make sustainable transportation more accessible?
