Skip to content

CO₂ Emissions calculation

Contact Info

  • Digitransit Team


Graph build import of CO₂ Emissions from GTFS data sets (through custom emissions.txt extension) and the ability to attach them to itineraries by Digitransit team. The emissions are represented in grams per kilometer (g/Km) unit.

Emissions data is located in an emissions.txt file within a gtfs package and has the following columns:

route_id: route id

avg_co2_per_vehicle_per_km: Average carbon dioxide equivalent value for the vehicles used on the route at grams/Km units.

avg_passenger_count: Average passenger count for the vehicles on the route.

For example:


Emissions data is loaded from the gtfs package and embedded into the graph during the build process.


To enable this functionality, you need to enable the "Co2Emissions" feature in the otp-config.json file.

  "Co2Emissions": true
Include the emissions object in the build-config.json file. The emissions object should contain parameters called carAvgCo2PerKm and carAvgOccupancy. The carAvgCo2PerKm provides the average emissions value for a car in g/km and the carAvgOccupancy provides the average number of passengers in a car.

Example configuration

// build-config.json
  "emissions" : {
    "carAvgCo2PerKm" : 170,
    "carAvgOccupancy" : 1.3


Config Parameter Type Summary Req./Opt. Default Value Since
carAvgCo2PerKm integer The average CO₂ emissions of a car in grams per kilometer. Optional 170 2.5
carAvgOccupancy double The average number of passengers in a car. Optional 1.3 2.5



OTP 2.5

  • Initial implementation of the emissions calculation.