Transportation tickets that show greenhouse gas emissions

As we pursue our mission to make the environmental impact of daily actions more visible and understandable, here’s an overview of how greenhouse gas (GHG) emissions are displayed in the transport sector. To explore this topic, we interviewed ADEME expert Marc Cottignies about the current regulations and their applications for citizens throughout various transportation services.

Marc, can you introduce yourself?

I’m Marc Cottignies, an expert engineer at ADEME’s Transport and Mobility Service, mainly focusing on three areas: quantifying the environmental impact of transport operations, voluntary commitments from freight transport clients and the aviation sector.

Can you summarize the key elements of French regulations on GHG information for transportation?

We generally talk about GHG information for transport services rather than "displaying" emissions, especially in freight transport. Transport providers are required to inform their clients about the greenhouse gas emissions associated with the services offered or performed. This aims to raise awareness among transport service users about environmental impacts, giving them access to environmental data, not just pricing or other factors like travel time and comfort.
It applies to both passenger and freight transport, as well as moving services, across all modes of transport. Initially, the regulation covered transport services to and from foreign countries, but it is now limited to operations within France.

In practice, the regulation imposes few specific requirements regarding how the information should be communicated to customers, leading to a variety of implementations: display on board certain buses, trams, or metro systems, information provided through the transport provider’s app, included on invoices, or simply made available on the website, etc.

Are there any European regulations to consider?

As of today, no European regulations exist on this subject.

However, French regulations are based on European standards and studies, such as EN16258:2012, which is currently being revised through the development of the international ISO14083 standard.

What changes are being discussed in the near and mid-term future?

There are many!

Overall, the priority should be improving the implementation of regulations across the entire sector, in quality and quantity.

Qualitatively, communication must first be structured and standardized so that the information effectively reaches the customer in an appropriate format. Then, the accuracy and precision of the reported values must be improved.

Quantitatively, efforts should focus on generalizing the measurement of emissions data and ensuring its transmission to customers by transport providers, as well as facilitating its use by customers.

The scope of application could be restored to its original state, meaning that all transport services between France and other countries would be reintegrated.

A voluntary external verification for transport providers would offer customers greater assurance and transparency. The regulatory framework allows for this, but its implementation is not yet possible. This issue needs to be resolved.

It is worth mentioning that ADEME is developing a solution to improve the exchange of environmental data between transport stakeholders, providing a structured framework to make GHG information communication more effective and efficient for customers. The first version of this platform, particularly designed for freight transport operators, was released in June and can be accessed via the EVE portal (under "Inscription").

Below are some snapshots of real-world examples (as of this day) showing what passengers see when searching or purchasing tickets. Marc Cottignies highlighted a lack of consistency, and we found this reflected in our research: missing, unclear, or hard-to-find information , displayed after purchase instead of before , not available across all formats (paper tickets, apps, websites, physical stations, etc.)

Train

On this platform, GHG emissions are displayed but not highlighted or explained. Is "1 kg of CO2" a lot for this trip? How does it compare to other modes of transport?

Likewise the information is visible (on both desktop and mobile) but lacks clarity.

On this other train booking site, GHG emissions are not displayed during the search or selection process.

The information only appears after selecting a ticket, and even then, it lacks context and explanation.

---

Route planning tools

On this mapping and itinerary tool, no GHG emissions information is displayed on desktop or mobile.

When the information is available, as on this trip comparison tool, it is well presented but missing for walking and cycling routes (even when the distance is reasonable for these options).

---

Bike-sharing services

Here are two bike-sharing apps where GHG information is displayed, and on one of them, it is explained in greater detail.

Often, using these services requires downloading the app, creating an account to access features like comparison and booking, and only then being able to view GHG information. Few services provide this information online quickly and without barriers (registration, download, purchase, etc.). As for its clarity, it is clearly a secondary concern.

---

Metro

For metro users, the website displays CO2 impact information and provides a comparison with the same journey made by car. However, few people can tell whether 11 g or 786 g is a significant amount. Our familiarity with this indicator is still too limited to fully grasp these figures. A quick link directs users to the operator’s carbon footprint report.

---

Bus & coach

This bus operator does not display emissions during the booking process. Instead, the only option presented is carbon offsetting.

---

Air travel

In the air travel sector, GHG information varies greatly and is often hard to find. One airline does not display any figures at all, opting instead for general communication. Another includes the ICAO emissions calculator, but it is placed at the bottom of the ticket in a way that is neither readable nor easily accessible.

Another airline offers an emissions calculator in Excel format, which can be downloaded and filled out but only for freight. While easy to use, it does not allow to measure emissions from passenger transport. Additionally, there is no information on the provided figures (source, company carbon footprint, etc.).

Here, this electronic ticket does not provide any figures and instead redirects users to the airline's website.

During the booking process, the information is presented differently depending on whether the user is on mobile or desktop. As for the quality of the information provided, we’ll let Valérie Masson-Delmotte comment on this rather limited display.

The information link redirects to carbon offsetting actions rather than the airline’s emissions calculator, which is well-designed and calculates the emissions for the journey.

---

This last example is significant because it shows that the information is not provided to the user; they must search for it, analyze it, and understand it (unlike price, duration, etc.). When it is displayed, the information is not complete (it does not include emissions related to fuel upstream of combustion), limited, difficult to interpret, or even misleading. Finally, different services do not always compare the same data, making it easy to make decisions with incomplete information.

It is clear that GHG impact display needs to improve in terms of visibility, clarity, and integration into mobility choices. So if you work in the transport sector (comparison tools, route calculators, mobility operators, etc.) and want to provide better insights for your user communities (who are increasingly demanding and expect transparency), you can find inspiration in the Impact CO2 simulator!