Green Travel Data is the outcome of the Green Travel Pledge which is the rail industry's commitment to provide detailed, accurate and reliable data on the carbon emissions of rail journeys so that:

• Travellers are empowered to make more informed choices through easy access to the sustainability credentials of their chosen journey
• The sustainability benefits of travelling by train become clearer and even more compelling.
• Travel retail and information providers can make data on rail journey emissions easier to access and use for the traveller;
• Businesses and travellers can accurately measure the emissions of their rail travel to track their progress against sustainability goals.
• The data will help encourage business and leisure travellers to shift away from more polluting modes such as car and plane, which will stimulate additional journeys by rail.

It is a rail industry initiative being led by the Rail Delivery Group (RDG), in partnership with Great British Railways Transition Team (GBRTT), creating a recognised industry benchmark for carbon emissions

Green Travel Data focuses on providing the most accurate data possible for rail journeys. We are also working to present it alongside accurate data of other modes of transport.

The calculation is per passenger. This takes into account occupancy data to provide a reliable figure for how many people will be using each route.

It is intended that Green Travel Data emission values for each journey will be displayed alongside journey results in journey planners and web ticketing services. An API is being developed to make it as easy as possible for retailers and information solution providers to consume the data.

No, there are many different methods for calculating carbon emissions for train journeys.

We believe it's important that the rail industry works from one reliable, accurate and consistent measurement of carbon emissions. That is why we are using granular data to make Green Travel Data carbon emission data as reliable as possible.

We plan to continue to roll Green Travel Data out to new travellers, additional businesses, online booking tools and travel management companies etc.

We have been working with carbon emission experts at Thrust Carbon and rail data specialists at Fab Digital to compile rail data and use it to accurately calculate rail emissions for all point-to-point rail journeys in Britain.

Data used includes engine type, fuel type, journey distance, number of carriages, travel class, occupancy and timetable.

Details of the full methodology used to calculate the figures is available via the Rail Data Marketplace.

Other emission measures, such as the one maintained by DESNZ (the Department for Energy Security and Net Zero) and still colloquially known as the 'Defra methodology', offer a general average emission figure for all customers on rail services in Britain. However, they do not differentiate between various factors including different classes of travel, load factor, or electric vs diesel power units.

The 'Defra methodology' calculates a single emission factor for the average passenger per kilometre, which, while useful for high-level comparisons, does not accurately reflect the emissions associated with individual passengers on specific journeys.

Our Green Travel Data methodology fills this gap, offering a more granular and nuanced understanding of rail emissions. It considers the specific characteristics of different rail routes and allocates emissions to individual passengers based on the following (not exhaustive): number of carriages dedicated to each class, the average load factor for each class, and the volume of trains run on each route.

This approach can provide a more accurate measure of the emissions associated with individual passengers and can serve as a powerful tool in enabling more accurate reporting on rail emissions for businesses, whilst also shaping strategies for emission reduction in the rail sector.

Our carbon calculations for rail take into account: engine type, fuel type, journey distance, number of carriages, travel class, occupancy and timetable.

We will update the data each time a new timetable is introduced. This can lead to a change in passenger behaviour, which can affect the passenger numbers on a particular route. Additionally the types of train that operate the service may change, leading to a different emission value for the train itself.

The scope and accuracy of the data is also evolving continually as we work to make our data as accurate and representative as possible. Recent changes that may have an impact include:

• expanding the scope to include weekends.
• updating the assumed car occupancy to better reflect leisure and business travel. (from 1 to 1.6 people per car).
• incorporating new data on the emission values of trains.

The Green Travel Pledge was the rail industry commitment to develop an accurate, consistent and independent set of sustainability data for the rail industry.

The output of the pledge is our Green Travel Data. As the data becomes more widely available, it will be referred to as Green Travel Data in future. We are developing a new kite mark for Green Travel Data so that you can know that your preferred supplier is using approved data when you see it.

Our methodology uses the number of carriages and number of passengers between any two station stops on a journey and aggregates these. As such, any joining or splitting of trains would be factored into the overall emission calculations for the route as this would alter the number of carriages and passenger load at the appropriate point.

Our methodology takes into account the type of train - electric or diesel - operating on specific routes. This allows us to estimate emissions accordingly. Where trains change from electric to diesel (and vice versa) en route, we will take this into account.

At this stage, we will not be factoring in 'one-off' train cancellations. We will only factor in changes if they substantially impact the rail timetable.

For these journeys, we are able to identify the emissions for each part of the journey, and as such can calculate the emissions for the entire route, even if the route is partially electric and partially diesel.

Only direct journeys are currently included. We have recently expanded the scope to cover journeys on all seven days of the week.

There is a small number stations with a direct service between them (approx. 1% of the total) that are not covered in the results.

These journeys are missing because passenger loading information isn't available for the current timetable, typically because the timetable has changed recently, or there is long term engineering work affecting services.

The initial focus of Green Travel Data was to cover the key business travel routes. The scope has now been broadened to cover all direct journeys, both business (B2B) and leisure (B2C).

As part of our ongoing analysis, we continually improve our algorithms and implement enhancements to achieve higher accuracy in our calculations. Additional data sets are also included when they become available. We also update the input data to reflect the latest timetable, train routing, rolling stock and passenger numbers at the time of publication. Any of these can result in variations in emission values.

Only direct journeys are currently included. If a journey includes a change of train, that journey is not currently covered by green travel data.

We are working to widen the scope to include indirect journeys in future phases.

Green Travel Data considers a number of factors to ensure that the results are specific to each route. The journey distance, the number of passengers making the journey, the number of carriages on the train, and the type of rolling stock used will influence the exact emission value.

Busier routes will see lower per passenger emission figures. On routes where older train fleets are currently used, the emissions may be higher. The results of Green Travel Data can be used to help inform future rolling stock replacement and electrification projects which will increase the sustainability of services across the network.

Car emissions are sourced from the Government's Department for Energy Security and Net Zero, Greenhouse gas reporting: using the latest published conversion factor, using the Business Travel - land data set.

Initially, as Green Travel Data was focused on business travel, the 'Executive car' kgCO2e per km figure value was used. As the scope has been expanded to cover leisure journeys too, the values now used are for the average car size.

The route distances were calculated using the OSRM (Open Source Routing Machine) project. Coordinates for each station pair were processed to determine the shortest road route. If a station wasn't directly accessible by public roads, the nearest accessible road was used.

By multiplying the 'kgCO2e per km' figures with the route distances, we calculate emission values for petrol/diesel, hybrid plug-in electric, and battery electric cars for each journey.

The emission value is then divided by the national average of 1.6 passengers per vehicle to calculate a per-passenger value.

It should be noted that in previous sets of data, car occupancy was assumed to be one person, which is typical of business travel. This change in occupancy has seen a reduction in the resulting per-passenger car emission values.

While train travel is usually greener than other modes of transport, emissions can be relatively high on a small number of routes. This variation can be due to a number of factors, including low passenger numbers or, as only direct journeys are currently covered, those direct journeys only occurring at less busy times.

An example of this is the result for journeys between Ipswich and Harwich International. The emission value is particularly high as there are only four direct trains between this station, all of which have lower passenger numbers. The majority of journeys between these two stations are indirect, and if taken into account, would reduce the emission value per passenger considerably.

The work to include both direct and indirect journeys in the results will form part of future phases.

No, the data is based on the planned, long term timetable which is refreshed twice a year. This doesn't reflect any short term variations but assumes typical conditions for the route. We plan to look at how real time variations can be covered in future phases.

Green Travel Data uses the UK Government's most recently released set of emission conversion factors, which are published by the Department for Energy Security and Net Zero (DESNZ).

Green Travel Data identifies all direct services between the two station and works out the emission value for each service (per km emission value for the booked train type x the distance).

The average passenger load on each train is derived from the passenger count for each station-to-station segment of the journey.

From these values, we calculate average emissions of trains specific to journeys between the specific to stations.

This energy value is turned into an emission figure by mapping to the UK Government’s Greenhouse Gas Conversion factors.

Green Travel Data per passenger emission figures take into account a lot more than just the distance of the journey.

 The type of train (and fuel it uses), the number of carriages that make up the train and the number of customers on the train (especially off-peak services that may be quieter at certain times of the day) can heavily impact the overall per passenger emission figure on each route.

Energy values per kilometre are derived for electric trains from Network Rail EC4T data. We are continuing to gather data from as many sources as possible to better improve our emissions calculations.

Green Travel Data uses MOIRA modelled data to derive the loading for each direct service between any two station pairs. From this we can work out the passenger mileage between those two points and from that the average loading value for all services. This data is currently derived from the May 2023 timetable. Future data publications will be updated to reflect the forecast for the latest timetable. Please refer back to the Green Travel Data website for any updates.

Yes the figures take into account travel in either direction.

Yes, as the data used includes passenger load, this will include all passengers on that train.

The scope of Green Travel Data has been expanded in include all journeys made, seven days a week.

Whilst Green Travel Data doesn't currently take short term engineering work into account, any buses operating as part of the long term (six monthly) timetable will be incorporated using emission conversion figures for local buses for the UK Government's Greenhouse Gas Conversion factors.

If a ticket is purchased for travel or a seat booking is made, then this would count towards the occupancy figures we use to calculate the per passenger emissions. There are some cases in which a pass or on the day upgrade is purchased, which may mean that we do not take then into account certain journeys.

Energy used on the train for heating food and drink, and energy required to move the portion of the train using by catering areas are included in the train emission figures.

How staff get to the station to support the running of the train is not included in this phase of the initiative but will be considered in planning future phases.

We have received data from the vast majority of train operators including all government contracted services. All routes are covered.

Timetables typically change every six months in the rail industry. Our figures will be updated to reflect any changes made in the timetable to train routes or passenger volumes.

We plan to refresh our data twice a year, in line with when new timetable data is published for the GB rail industry.

The results are based on the timetable that was current between June and December 2024. A process will be put in place shortly to refresh data to incorporate the latest timetable which runs from December 2024 to May 2025, and passenger loads twice a year after each timetable change.

Passenger forecasted data is used for the Green Travel Data, which includes first class data captured at the point of sale.

First class ticket upgrades, whether through an external auction site, operators own upgrade pre departure site, walk up upgrades, on board upgrades are not currently included, however we are looking at how this can be incorporated, in future phases.

Some train operators under instruction from the Department for Transport (DfT) have withdrawn First Class from their services, in these cases, all travellers are considered to be travelling in standard class accommodation.

On certain routes and certain journeys, first class accommodation is made available to standard class passengers due to high passenger loads, our model assumes passengers will be travelling in the class of accommodation of the ticket they purchased.

The scope of Green Travel Data has been expanded to include figures for passengers travelling in first class and standard class separately, as well as a combined average figure for both classes. The method of calculation for each class of accommodation has been improved to better reflect the additional space taken up by each first class seat where this is the case.

We consider Standard Premium as Standard travel for the purposes of calculating rail emissions.

We'll be exploring methods to incorporate cost measurements into our data (including potential visualisation in £/$/€ per head/household) in the future.

We are continually working to further widen the scope of the Green Travel Data. Planned enhancements /considerations include:

• Incorporating real time variations to the timetable, rolling stock and passenger numbers
• Providing results for indirect journeys
• External ISO accreditation of Green Travel Data
• First and last mile (by other transport modes)
• Provide the data in an API so that it can be incorporated into point-of-sale information systems such as journey planners.

Data is now available for all direct journeys. We hope to expand this to cover all indirect journeys in future phases and create an API which will be available for all retailers to consume at point of sale.

Currently we have data for direct journeys i.e. those with no changes. Where more than one train operator runs trains on that route, the data for each will be used to calculate the final figure.

However, in future phases we plan to include indirect journeys (those with changes), allowing rail users to have access their emissions values for multiple legs of a journeys.

Where regularly scheduled direct flights operate between cities where there is a corresponding direct rail service, comparative figures for the journey by air are included in the results.

Where flights operate to multiple airports (e.g. flights from Edinburgh operate to London Gatwick and London Heathrow) the air figures reflect the mean figure of the two routes.

Green Travel Data uses the UK Government's most recently released set of emission conversion factors for domestic flights which are published by the Department for Energy Security and Net Zero (DESNZ). These figures are based on the average emissions of all domestic UK flights which reflects the fact that Green Travel Data has been expanded to include both business and leisure travel.

The DESNZ figures are based on the average split between economy and business class travel, taking into account that business class is not available on many domestic flights.

This isn't currently available as part of Green Travel Data data, however we are looking to include indirect factors for all transport modes in future phases.

Green Travel Data has used the latest available UK Government’s Greenhouse Gas Conversion factors and the Business Travel by land - Unknown category for car emissions, which covers diesel and petrol cars.

Green Travel Data has used the latest available UK Government’s Greenhouse Gas Conversion factors for car emissions which covers battery electric cars.

This energy value is then turned into an emission figure by mapping to the UK Government’s Greenhouse Gas Conversion factors.

Not at this stage as we have focused purely on the rail journey emissions. Future phases will make our rail data available for consumption by various multi-modal journey planners and e-ticketing systems.

At this stage, rail freight is not part of the calculations. However, we understand there is a huge environmental benefit to rail freight's role in removing HGV congestion from our roads and are exploring opportunities to include rail freight calculations moving forward.

Green Travel Data data has been expanded to cover travel seven days a week and also leisure and business travel. As such, we are looking to incorporate it into any future campaigns.

Yes, our calculations for car are a basic average figure for all vehicles used on British roads. While initially, data was presented on the assumption of one person in each vehicle (which is typical for business travellers), as we have now expanded Green Travel Data to include leisure travel as well, the national average occupancy on a car is now being used in our calculations.

We have developed a new rail carbon calculator which provides detailed, accurate and reliable data on the carbon emissions of rail journeys to businesses at the point of sale.

This new tool allows businesses and business travellers to easily demonstrate the green credentials of switching to rail travel from less environmentally-friendly alternatives such as car and plane travel.

We want to help encourage businesses to modal shift away from car and plane travel to stimulate additional business journeys by train.

Please contact us at This email address is being protected from spambots. You need JavaScript enabled to view it. to discuss your involvement with the Green Travel Data project.

If you would like additional details on Green Travel Data, or you're a business, travel management company or online booking tool provider who would like access to this data, please contact This email address is being protected from spambots. You need JavaScript enabled to view it..

Central to the ethos of Green Travel Data is the aim to develop and set of data that is accurate, impartial and trustworthy. To achieve this, we have word with sustainability experts to ensure our methodology that meets these aims. 

In addition, we have worked closely with the UK Statistics Authority to ensure that our methodology follows their Code of Practice for Statistics for official statistics. Having demonstrated our commitment to Trustworthiness, Quality and Value we have been added to their list of Voluntary Adopters of the Code. 

Read our Statement of Voluntary Compliance here. 

In addition to this, we are in the process of attaining ISO 14083 Accreditation which relates to the quantification and reporting of greenhouse gas emissions arising from transport chain operations. 

Many tickets offer "any route permitted" travel between two stations so we provide a figure for the station-to-station journey, which averages out all rail services running along that route to take into account the flexibility provided. The exception would be if your fare specifies only a specific route; in that case we will calculate it according to the train operator providing that specific service and route.

We plan to release an open API/data feed in the next phases to allow travel management companies, online booking tools and other business travel providers with the opportunity to consume the carbon emission data and supply it to business travellers at the point of sale.

Green Travel Data carbon emission data is available via the Rail Data Marketplace (RDM). RDM is a central platform for finding and sharing rail data, allowing us to share data with multiple parties quickly and easily via a number of formats.