Quiz: Which is the most eco-friendly mode of transportation?

The automotive and transportation industry has long been taking incremental steps toward making mobility more sustainable. Dieselgate put that slow shift into high gear.

As cities become more congested and more connected, the push for sustainability has led to the development of creative alternative means of transportation beyond the confines of traditional vehicles like cars, trains or buses.

Many new types of vehicles claim to be eco-friendly, but how 'green' are they, really? 

How about hailing a ride from the comfort of your phone?

On-demand taxis, ride-hailing apps like Uber, Yandex, Didi, etc. and even traditional carpooling eliminate the need for commuters to have to take their own cars. There are fewer cars on the road and less traffic – in theory.

The reality is that these apps have made getting a ride so convenient, easy, and cheap, that people are taking on-demand over public transport. Unfortunately, Lyft hasn't left more personal cars at home, but instead made people take the subway less often. The demand for these services is so high that it’s led to more congestion in urban areas where space is already scarce. Even if the cars are fully electric, more traffic is not eco-friendly.

Are two wheels are better than four?

The saying “don’t be gentle, it’s a rental” definitely also applies to shared bikes. Riding a bike in itself emits 0g of CO2, but this fails to account for the environmental impact caused when producing the bike and transporting a whole fleet of them to their final location.

But it's the vandalism of bikes that is by far the least eco-friendly thing about them. The lack of personal accountability seems to inspire the worst in people, making them destroy, misuse, and discard bikes wherever they want. It appears that people need to have ownership over vehicle property in order to prevent them from behaving like total hooligans.

You’ve seen those images of the massive bike graveyards, right?

What about taking the bus?

Public transport overall is generally considered to be one of the better options when it comes to reducing the negative environmental impact of urban mobility.

Taking a bus, even if it runs on diesel, as the majority do, is exponentially better than taking an electric car or taxi. The problem is it’s rarely the transit mode of choice for the typical commuter – nobody likes bumping into a sweaty stranger’s armpit on their way to work when a crowded bus takes a sharp turn.

Put your best foot forward

Walking, running, jogging, strolling – whatever your pedestrian preference, it objectively has the lowest ecological impact by far. It’s great for you to keep active, and it’s not hurting the environment per se, although it is worth mentioning that the carbon footprint of the average running shoe ranges from 18-41kg CO2** per pair during production.

A green vision of the future?

Calculating the environmental impact of electric ‘Air Taxis’ – eVTOL (electric vertical take-off and landing) aircraft – is significantly more complicated than that of cars. For one, this technology is still in its infancy and thus there aren‘t (m)any studies on its environmental effects.

The emissions from air taxis also depend heavily on the aircraft design, distance traveled, and the load carried. One study* cites that on a 100km journey with three passengers, VTOLs have six percent lower emissions than EVs. On journeys of 35km, their emissions break even with those of gas-powered cars.

We’ll have to wait and see on this one as the technology matures and air taxis come to market at a larger scale.

Shared electric scooters beat jams

Compared to the greenhouse gas emissions of a regular motorcycle, which average 107g/km CO2, a shared electric two-wheeler is the better choice. They’re also lighter and consume less energy than electric cars, and they have 30x the battery capacity*.

With dockless shared e-bikes, you run into similar problems as with shared bicycles – people will misuse them. This causes the lifecycle of an e-bike to be dramatically reduced versus a personal one, thus needing to be replaced more often and having a larger ecological impact.

Join the scourge of the inner-city footpath

In some cities, electric kick scooters from different companies racing to be the first to market have descended upon unsuspecting citizens like a biblical swarm of locusts.

It happens really fast. First, you start to see them everywhere. Then, you notice they’re being left in places where they shouldn’t be – in the trash, angrily piled on top of each other, and even thrown into the river. A week later, the company cuts its losses and shuts down operations in that city.

Not quite sustainable yet – as a form of mobility, or as a business model. While there are dozens of companies trying, no one's cracked the dockless micromobility model yet. I'll eat my hat when they do.

How about the future of cars?

Compared to gas-guzzling internal-combustion-engined cars, electric vehicles are leading the charge to environmentally-friendly mobility. But how much of this public perception is reality, and how much is ‘greenwashing’?

While EVs are being marketed as the zero-emissions, sustainable alternative in light of Dieselgate, the reality isn’t as black and white. The process of mining lithium to produce EV batteries is quickly becoming an irreversible environmental catastrophe, which begs the question: is the grass always greener on the other side?

Let the train take the strain

Trains, trams, metro, subway, underground, tube, U-Bahn, S-Bahn – there are a lot of differences among these vehicles like capacity, speed, energy efficiency, engine type, and so on that can influence their environmental impact, so the numbers above are only meant to reflect the broader category of railway transit.

Zooming out to the larger mobility landscape, we can agree that traveling by rail-based public transport removes cars from the road, lowers emissions and is cheaper than personal vehicles. Not to mention that the majority of trains in Europe already run on renewable energy.

So, who wins?

By our own grading system, the most environmentally friendly mode of transportation is clearly walking, with other forms of public transport in second and third place. But realistically, the answer is not so simple.

Every human on earth has an individual and multimodal travel chain. It's (almost) impossible to find a person who only uses a single mode of transport in a week, let alone a month, a year, or a lifetime.

No one expects you pull a Forrest Gump and forgo every modern form of transportation. Sometimes you need to go to Ikea. Sometimes you need to fly across the Atlantic. Sometimes it's absurdly expensive to take a 6h train to another city so you opt for a 45 minute, €90 short-haul flight instead. Sometimes it's raining and it's cold and you're lazy. Sometimes you're in a rush. Sometimes it isn't safe.

And a lot of the times, the commuting distances are too far and public transport isn't available or convenient. Even if we only consider people who live in urban areas, it's not feasible for everyone to walk to and from work every day. Not every city is walkable or even moderately pedestrian-friendly and not every person is physically able to walk the 'last-mile' from public transport to the final destination.

And even if a city has the best possible public transport infrastructure and service, the convenience of ride-hailing services like Uber is too tempting to pass up. We're only human.

With electric cars, we're only starting to scratch the surface of the environmental damage caused by mining lithium, so it's debatable whether they're ultimately 'cleaner' than gas-powered vehicles throughout their lifecycles. Perhaps, the example of the EV grey area could one day also parallel to electric air taxis and how 'green' they really are, but it's too soon to have any real data to forecast the environmental impact of eVTOL aircraft.

In the sharing sphere, the lack of private ownership seems to make it acceptable for people to treat cars badly. The constant mistreatment of shared vehicles leads to more required maintenance, more frequent repairs, higher costs, and a shorter lifespan than personal cars. This arguably has a worse environmental impact than if people owned, used, and cared for their own cars. Shared micromobility services face similar problems that no company has successfully cracked. Yet.

Dockless last-mile services like e-scooters and bikes tornado through towns shouting green buzzwords like 'sustainable,' 'eco-friendly,' and 'zero-emissions' while leaving metric tons of trashed vehicles in their wake. The more awareness and alarm there is over the catastrophic effects of climate change, the more 'greenwashing' we need to watch out for.

Remember to think big...

It's important for citizens to look at the bigger picture and consider sustainable mobility from every angle, both at the local, and the global scale. Of course, I'm certainly not advocating for people to give up on electric and/or shared mobility and go back to driving a gas-guzzling SUV for a quick trip to the grocery store.

• Read Automotive IQ's Guide to Real Driving Emissions testing

I'm not saying it's pointless for aerospace companies to invest considerable resources into the research and development of 'greener' aircraft concepts. In terms of sustainability, there simply isn't a perfect vehicle or transportation behavior – I'm saying that not as a nihilist, but a realist.

There's a lot of false 'eco-friendly' advertisement and not everything is as green as it seems. However, it's absolutely worth it for people, companies, and governments to go all-in in this direction. There's no Plan(et) B.

We have a lot of power as consumers. While environmental policies and regulations can influence environmental decisions at a larger scale, our individual choices have a lot more influence than you'd think. Our collective behavior sets the tone for company strategies and leads to better products and services.

So, as concerned citizens and proponents of sustainable mobility, there's a lot we can do to move the needle while we wait for environmental legislation to be written and green technology to be developed.

... even starting small still makes a difference

Even one small change in our daily routine can reduce the carbon footprint of our individual travel chain. For one, we can walk if and when we are able to. Pick a good podcast and take a long stroll after work to unwind, watching one neighborhood slowly change into another. The best way to get to know a city is by hitting the pavement. If it's available, always opt to take public transport. You can bring a book, your favorite guilty-pleasure gossip rag, a challenging Sudoku, play Fortnite on your phone, or even just people-watch.

A good rule of thumb is the more people being transported within one vehicle at one time, the better it is for the environment. For those cold, rainy, lazy occasions where you just want to get a car to take you directly home as fast as possible, services like Clevershuttle are an alternative to taxis.

A hybrid between Uber Pool and a public bus, it has all the convenience of ride-hailing services, except it's cheaper, electric, and can fit a whole bachelorette party gang. Needless to say, I'm a huge fan and anxiously await the day when more services like it are ubiquitous and the range of areas served is a lot larger.

The environmental impact of mobility is not a Scarlet Letter defined by the CO2 emissions figures on each individual vehicle. It's an accumulation of small choices in our everyday transportation behavior that leads to reducing the negative environmental effects on our cities, our countries, and our world. There's no undoing the damage already done, but it's our global collective duty to try.

We should consider sustainability in transportation as a core value guiding our mobility behavior – and the automotive and transportation industry as a whole – toward a better, more sustainable future.

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