Conversion of transport data to footprint
Get footprint in kilograms of CO2-equivalents for transport usage by category. Compare different modes of transport on equal grounds and promote sustainable travel
All inputs, outputs and defaults can be seen in the Convert transport technical API docs.
Inputs
This endpoint receives:
- a data source to base calculations on
- a list of transport categories, associated to a value and its unit as well as occupancy rate
- optionally the date for which the footprint should be computed
At least one category must be provided. Values of either kilometres travelled, kWh used (for electric cars) or days (for cruise journeys) are optional. If no values are given, you get the conversion factor for the given category in return. The occupancy rate of the chosen category is optional input. If no occupancy rate is given, the annual average for that mode of transport is taken as default. If no date is given, the current date is taken as the default.
Outputs
This endpoint returns, for each category:
- footprint in kilos CO2e, rounded to grams
- footprint broken down into the different lifecycle phases (production, use-phase and infrastructure) to highlight the contribution of each phase towards the total footprint
Note that the footprint for transport includes the full life cycle emissions, for consumer communication, which goes beyond the requirements of greenhouse gas reporting. If you’re interested in the GHG reporting use case, head over here.
Categories
Categories are grouped for visibility into modes of transportation: road, rail, air and maritime. Level 1 categories are averages of different modes of propulsion and travel patterns (long and short distance travel in some cases because of differences in vehicle types used, occupancy and emission profile). Level 2 categories are available as climate calculator input. Level 3 categories add extra detail for converting travel data to footprint.
| Road transport categories | Lvl. | Description |
| privateCar | 1 | Average of all four-wheeler private vehicles |
| electricCar | 2 | Electric car |
| hybridCar | 2 | Hybrid car |
| fossilCar | 2 | Gasoline or diesel car |
| sharedCarAverage | 1 | Average of all four-wheeler cars belonging to a car collective |
| sharedCar | 2 | Average of all four-wheeler cars belonging to a car collective |
| fossilSharedCar | 3 | Gasoline or diesel car belonging to a car collective |
| electricSharedCar | 3 | Electric car belonging to a car collective |
| hybridSharedCar | 3 | Hybrid car belonging to a car collective |
| taxi | 1 | Average of taxis |
| fossilTaxi | 3 | Taxi running on gasoline or diesel |
| hybridTaxi | 3 | Taxi powered by a hybrid propulsion system |
| electricTaxi | 3 | Taxi powered by electric motor |
| motorbikeAverage | 1 | Average of motorized two-wheeler vehicles |
| motorbike | 2 | Average of motorized two-wheeler vehicles |
| fossilMotorbike | 3 | Gasoline or diesel motorbike |
| electricMotorbike | 3 | Electric motorbike |
| bus | 1 | Average of all bus journeys and different propulsion types |
| busShort | 2 | Average of short bus trips |
| bioGasBusShort | 3 | Intra-city bus running on biogas |
| dieselBusShort | 3 | Intra-city bus running on diesel |
| electricBusShort | 3 | Intra-city bus powered by an electric motor |
| hybridBusShort | 3 | Intra-city bus powered by a hybrid engine |
| busLong | 2 | Intercity bus trips |
| micromobility | 1 | Average of micromobility transportation modes |
| walkBike | 2 | Walking/cycling |
| electricBike | 2 | Private electric bicycle |
| electricScooter | 3 | Electric scooters (Lime, bolt etc.) |
| Rail transport categories | Lvl. | Description |
| trainAverage | 1 | Average of trains |
| train | 2 | Average of trains |
| dieselTrain | 3 | Train powered by diesel engine |
| electricTrain | 3 | Train powered by electricity |
| Air transport categories | Lvl. | Description |
| flight | 1 | Average of passenger flights |
| flightDomestic | 2 | Less than 500 km |
| flightContinental | 2 | Between 500 km and 2000 km |
| flightGlobal | 2 | More than 2000 km |
| Maritime transport categories | Lvl. | Description |
| boat | 1 | Average of maritime transport modes (cruise, motorboats, ferry) |
| cruiseBoat | 2 | Cruise boat for long journeys |
| electricMotorBoat | 3 | High-speed boat powered by electric motor |
| fossilMotorBoat | 3 | High-speed boat powered by fossil fuel |
| ferryCarPassenger | 3 | Passenger traveling by car on a ferry |
| ferryFootPassenger | 3 | Foot passenger on a ferry |
Calculations
Emissions per kilometer are based on average vehicles in each category. If you have a large and old car, actual emissions would be higher than what you see in our calculations. Emissions per kilometer are calculated based on the life cycle emissions of the vehicle, which includes production, use-phase, maintenance, end of life and even infrastructure usage. The use-phase emissions for electric vehicles are calculated based on the European average electricity mix. The use-phase emissions for fossil vehicles include a well-to-wheel factor, which takes into account the emissions arising from upstream processes of fuel production like extraction, refining and production of the fuel. Newer mobility services, like shared micromobility, have additional impacts related to operational services, which has been accounted for in the calculations.
The distribution of different vehicles (cars, buses, motorbikes) by mode of propulsion (fossil, electric and hybrid) is taken from SSB’s statistics on registered vehicles by type of fuel for Norway, from UNECE statistics on road vehicle fleet by fuel type for the UK and from the Ministry of Economy, Trade and Industry’s statistics on vehicle fleet type for Japan . For flights, the distribution between domestic, intra-EU and international journeys is taken from Eurostat’s data on air passenger transport. For all other modes of transport, we assume an even split between all the subcategories.
The default emissions per passenger-kilometer is calculated using the annual average occupancy rate for that specific mode of transport. The number of passengers on-board a vehicle has a significant effect on the footprint of a journey. Traveling on a bus which is fully occupied will have a lower footprint than traveling on a bus which is half empty, as the emissions from the journey are distributed between a greater number of people. The default occupancy rates used for different modes of transport and their respective sources can be seen below:
| Transportation mode | Default occupancy rate | Source |
| Intra-city bus | 32% | SSB, transport by bus in city areas |
| Inter-city bus | 33% | SSB, public-founded routes |
| Electric train | 32% | Vy, annual report |
| Diesel train | 35% | NSB, sustainability report |
| Domestic flights | 87% | Norwegian Annual Sustainability report |
| Intra-EU flights | 76% | SAS Annual Sustainability report |
| International flights | 76% | SAS Annual Sustainability report |
Sources
Car (electric, hybrid and fossil)
The multipliers for electric, hybrid and fossil cars are calculated based on several sources. The production emissions for electric and hybrid battery packs are from Ellingsen et al. (2014), while production emissions for the vehicles themselves as well as maintenance are obtained from a 2018 EU Parliament report on the market development of battery electric vehicles. Use phase emissions are data source dependent. For Norway, average tailpipe emissions data for fossil vehicles is used, while we estimate the emissions for electric vehicles based on our electricity mix factor along with electricity consumption data from the aforementioned references. For other data sources, average use phase emissions from the 2018 EU Parliament report are used. We also factor the effect of increasing passenger mass on the fuel/energy consumption of the vehicle. Based on this study, for every 100 kg increase in vehicle mass, the fuel consumption increases by around 5%.
Carsharing
For a typical shared car, the assumption is that it has on average 10 users. The production, maintenance and end-of-life emissions of the vehicle are allocated equally to all users, meanwhile the use-phase emissions are allocated based on the kilometers driven by the user. We also factor the effect of increasing passenger mass on the fuel/energy consumption of the vehicle. Based on this study, for every 100 kg increase in vehicle mass, the fuel consumption increases by around 5%.
Taxis
We use the emissions per kilometer of different types of cars (electric, fossil and hybrid) and combine it with average occupancy rates of taxis obtained from SSB, to get the multipliers for taxis.
Motorbike (electric and fossil)
The multiplier for fossil motorbikes is calculated based on data from Motorvognregisteret . The Motorvognregisteret has data on the total emissions from different transport fleets which is then combined with average distance driven to calculate the emissions intensity in grams of CO2e/km.
The multiplier for electric motorbikes is obtained from this study by ITF. The study assumes a lifetime of 10 years with an annual mileage of 4900 km/year for the calculations.
Bus (short and long distance)
The multipliers for buses differ based on the type of prime mover (diesel, biogas, electric) and the distance traveled (intra and inter-city). The lifecycle emissions are based on this study by Brian Cox (2018). The numbers from the study are combined with occupancy rates to get the multipliers in emissions per kilometer per passenger. We also take into account the effect of occupancy rate on the energy use of the vehicle. At higher occupancy rates, the vehicle weight is greater, which results in increased energy consumption. This study defines the correlation between passenger mass and the energy use of the vehicle, which is used in our calculations.
Walking and biking
Walking and biking are considered as a single input and we assume the multipliers for both modes of transport to be zero. This means that both are considered to be carbon-neutral modes of transport.
Micromobility (electric options)
The multiplier for electric bicycles is based on an LCA performed by Felipe-Falgas, Pol, Cristina Madrid-Lopez, and Oriol Marquet. 2022. The electricity mix of the city of Barcelona is used to calculate the emissions from the use stage.
The multipliers for electric scooters are taken from the study Environmental performance of New Mobility by the ITF. The study assumes a vehicle lifetime of 2 years and an annual mileage of 2900 km/year for the calculations. The emission impacts related to operational services were assessed based on the amount of travel by service vehicles to enable effective operation.
Train (diesel and electric)
We have distinct multipliers for diesel and electric trains. The infrastructure and production related emissions are taken from this study on the environmental analysis of railway infrastructure. Yearly reports from Vy and NSB are used to get the average energy use of different types of trains. The energy use is converted to CO2 emissions using the European average electricity mix. At the end, the lifecycle emissions (production, use-phase and infrastructure) are combined with the occupancy rate to obtain the final multipliers in emissions per kilometer per passenger.
Flight (short and long distance)
The use-phase emissions for flights are taken from the greenhouse gas conversion factors by DEFRA, which specifies emissions for domestic, international and global/long haul flights. The numbers in this report are based on a mix of different types of aircraft. Additionally, a WTT factor for aircraft fuel and a factor of 1.8 for radiative forcing has been added, based on the work of Lund et al. (2015). We also include the emissions arising from the production of the aircraft and infrastructure use, based on the work of Chester (2007).
Motorboat (fossil and electric)
The multiplier for fossil-powered motorboats is taken from this study by TOI.
The multipliers for electric motorboats are taken from the study LCA of express boat propulsion systems. The study is a cradle-to-grave LCA with a 10 year period of operation.
Cruise
Section under construction.
Ferry (Car and Passenger)
The multiplier for ferries is based on the greenhouse gas conversion factors by DEFRA. Using operator provided information, a multiplier in passenger-km has been calculated for a RoPax (roll on/roll off a passenger) passenger ferry. CO2 emissions for foot-only passengers and passengers with cars are allocated based on the weight (passengers with a car have larger weight and hence are allocated a greater share of the emissions as compared to foot passengers).
See also intro to convert endpoint methodology for an overview of related endpoints.
Note that the related convert finance endpoint can convert a travel expense into footprint.