CO2MPAS

CO2 Model for PAssenger and commercial vehicles Simulation
Fact Sheet

Source: Commission modelling inventory and knowledge management system (MIDAS)

Date of Report Generation: Mon Apr 22 2024

Dissemination: Public

© European Union, 2024

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Overview

Acronym

CO2MPAS

Full title

CO2 Model for PAssenger and commercial vehicles Simulation

Main purpose

CO2MPAS is a vehicle simulation model for the calculation of CO2 emissions, energy, and fuel consumption from passenger cars and light commercial vehicles. It uses experimental data, retrieved from chassis dyno or on-road tests, to simulate the operation of vehicles under different operating conditions.

Summary

CO2MPAS is a technology-based vehicle simulation model developed to estimate CO2 emissions, energy, and fuel consumption of passenger cars and light commercial vehicles. CO2MPAS was developed to calculate CO2 emissions of light duty vehicles over the NEDC test cycle and protocol,  using as input, data retrieved from tests performed in accordance with the new emissions type approval test, i.e.  WLTP (Worldwide harmonized light vehicles test procedure set out in Commission Regulation (EU) 2017/1151). The WLTP is the new and more realistic procedure for the emission type-approval of light duty vehicles which replaces the old and outdated NEDC procedure starting from 2017. The use CO2MPAS for the purpose of correlating CO2 emissions determined on the NEDC and the WLTP is set out in Commission Implementing Regulations (EU) 2017/1152 (light commercial vehicles) and 2017/1153 (passenger cars). The correlation of CO2 emission values is required to ensure a transition from NEDC based CO2 emission targets to targets based on WLTP emissions under Regulation (EU) 2019/631 setting out CO2 emission performance standards for light duty vehicles.

The CO2MPAS model is able to provide the difference in CO2 emissions under the two different test procedures, thus allowing the evaluation of an NEDC-based CO2 value. For doing so it uses of technical information concerning the technology configuration of a vehicle and the WLTP-based CO2 test results.

As a vehicle simulation tool, the application of CO2MPAS can be used for other purposes than the WLTP/NEDC correlation. Notably, the model can be used to simulate a large number of variations in vehicle configuration, type, characteristics and technology, allowing for a quick estimation of CO2 emissions from different types of light duty vehicles. In this way it might be integrated in i) a traffic simulation model to evaluate the effect on the overall energy/fuel consumption of policies and measures on the transportation system, or ii) to a fleet simulation model to evaluate the effect on energy/fuel consumption due to the introduction of new vehicle technologies.

CO2MPAS is also the simulation model that was used to calculate fuel consumption and CO2 emissions estimates provided by the JRC’s Green Driving tool, an on-line tool that calculates realistic fuel consumption values over specific routes depending on a vehicle characteristics (https://green-driving.jrc.ec.europa.eu).

Model categories

Transport

Model keywords

road transportvehicle simulationCO2 from light duty vehicles

Model homepage

https://co2mpas.readthedocs.io/en/stable/

Ownership and Licence

Ownership

EU ownership (European Commission)

Ownership details

The model is being developed and maintained by the JRC.C.4 Unit who entirely owns the intellectual property of the tool.

Licence type

Free Software licence

The license grants freedom to run the programme for any purpose; freedom to run the program for any purpose; freedom to study (by accessing the source code) how the program works, and change it so it does enable computing; freedom to redistribute copies; and freedom to distribute copies of modified versions to others.

Details

Structure and approach

CO2MPAS is coded in PYTHON v3.4 computer language. It is based on vehicle longitudinal dynamics and has a modular architecture. It includes a series of predefined algorithms for simulating the operation of various components. It has the capacity to self-calibrate based on given experimental data.

Input and parametrization

The primary use foreseen for the model is to correlate type approval CO2 emissions determined for light duty vehicles in accordance with the new WLTP test procedure set out in Commission Regulation 2017/1151 with the CO2 emissions determined pursuant to the old NEDC test procedure set out in Commission Regulation (EC) No 692/2008. The CO2MPAS model calculates CO2 emissions of light duty vehicles on the NEDC test procedure using as input data retrieved during the vehicle type-approval carried in accordance with the WLTP test procedure (Commission Implementing Regulations (EU) 2017/1152 and 2017/1153, hereinafter ‘Correlation Regulations’)). The correlation procedure and the model allows the transition from the NEDC to  the WLTP without affecting the CO2 targets defined in Regulations 443/2009 and 510/2011 (replaced since 1 January 2020 by Regulation (EU) 2019/631). The model requires an extensive list of inputs, as set out in Table 1 of Annex I to the respective Correlation Regulations, in order to ensure the required level of accuracy in the correlation of the CO2 emission values. The inputs include in brief:

  • type of fuel
  • engine/powertrain characteristics
  • gear-box characteristics
  • electric components
  • vehicle characteristics
  • specific technologies of the vehicle
  • the results of the vehicle tested under WLTP conditions.

A number of default input values are defined for vehicle classes for the model to be used for other purposes. For example it might be used to carry out scenario analyses on the effect on global CO2 emissions due to the introduction of specific vehicle technologies in the vehicle fleet, or to assess the effect of modifying some aspects of the vehicle type-approval test. In this case achieving high accuracy on the single estimation is not important and the default values can allow its use to derive aggregated statistics.

Main output

CO2MPAS is able to provide fuel consumption, energy consumption and CO2 emissions for a vehicle following a predefined trajectory. Default simulation conditions are the NEDC and WLTP test procedures, for which it has been designed. 

Spatial & Temporal extent

The output has the following spatial-temporal resolution and extent:

ParameterDescription
Spatial extent / country coverageEU Member states 27
Spatial resolutionEntity
Vehicle
Temporal extentOther
Depending on trip/cycle duration <day
Temporal resolutionSeconds
The simulation is carried out considering a frequency of 1Hz in the vehicle operations. Higher frequencies can also be accepted.

Quality & Transparency

Quality

Model uncertainties

Models are by definition affected by uncertainties (in input data, input parameters, scenario definitions, etc.). Have the model uncertainties been quantified? Are uncertainties accounted for in your simulations?

yes
The model is regulated and its calibration is based on experimental data that are generated during the official vehicle certification test. Each new model version is released with a validation report that is available on the CO2MPAS Reports site.

Sensitivity analysis

Sensitivity analysis helps identifying the uncertain inputs mostly responsible for the uncertainty in the model responses. Has the model undergone sensitivity analysis?

yes
By the JRC the results were presented to the technical working group overlooking CO2MPAS development (see next point).

    Have model results been published in peer-reviewed articles?

    yes
    An ad-hoc technical working group was established by DG CLIMA during the development phase (comprised of industrial and independent stakeholders). Additional external validations are carried out on a yearly basis.

      Has the model formally undergone scientific review by a panel of international experts?

      Please note that this does not refer to the cases when model results were validated by stakeholders.

      no

        Model validation

        Has model validation been done? Have model predictions been confronted with observed data (ex-post)?

        yes
        The model is used on a daily basis by type approval authorities across Europe. JRC receives continuous feedback on its operation. In addition to this a dedicated validation based on 50 light duty vehicles has taken place.

          Transparency

          To what extent do input data come from publicly available sources?

          This may include sources accessible upon subscription and/or payment

          Based on both publicly available and restricted-access sources

          Is the full model database as such available to external users?

          Whether or not it implies a specific procedure or a fee

          no
          There is no underlying database. Input data to use the tool are technical vehicle information.

            Have model results been presented in publicly available reports?

            Note this excludes IA reports.

            yes

            Have output datasets been made publicly available?

            Note this could also imply a specific procedure or a fee.

            no
            This is s part of the vehicle certification process.

              Is there any user friendly interface presenting model results that is accessible to the public?

              For instance: Dashboard, interactive interfaces...

              no

                Has the model been documented in a publicly available dedicated report or a manual?

                Note this excludes IA reports.

                yes

                Is there a dedicated public website where information about the model is provided?

                yes

                Is the model code open-source?

                yes
                It is a JRC developed open-source software. All sources are available online.

                Can the code be accessed upon request?

                not applicable

                The model’s policy relevance and intended role in the policy cycle

                The model is designed to contribute to the following policy areas

                • Climate action
                • Energy
                • Institutional affairs
                • Transport

                The model is designed to contribute to the following phases of the policy cycle

                • Anticipation – such as foresight and horizon scanning
                • Evaluation – such as ex-post evaluation
                • Formulation – such as ex-ante Impact Assessments
                • Implementation – this also includes monitoring

                The model’s potential

                CO2MPAS is used to analyse the correlation between the CO2 emissions from the Worldwide harmonized light vehicles test procedure (WLTP) and the New European Driving Cycle (NEDC) test procedures. The WLTP is a new test procedure developed at the UN/ECE level that the Commission has introduced (in the place of the NEDC) for the type-approval of passenger cars and light commercial vehicles starting on September 1st, 2017 (EU Regulation 1151/2017).  The CO2MPAS model is used by vehicle manufacturers and type-approval authorities during the WLTP phase-in (2017-2020), to calculate the equivalent NEDC CO2 emissions for vehicles tested on the WLTP. In this way, the CO2 emission targets set by Regulation (EU) 2019/631 can remain unchanged in spite of the introduction of the new procedure.

                Commission Implementing  Regulations 2017/1152 and 2017/1153 provide for the use of CO2MPAS during the vehicle type-approval process.

                An extended version of CO2MPAS has been used in the Impact Assessment for the “Review of Regulations setting emission performance standards to establish post-2020 targets for cars and vans" (see [1]) in order to calculate the baseline 2015 CO2 emissions from the European fleet of new passenger cars under WLTP conditions.

                CO2MPAS to the Commission Roadmap:

                • Primary:
                  • CO2MPAS can also be used to provide “Data, analysis and intelligence for the Energy Union: initiative pooling and making easily accessible all relevant knowledge in the Commission and Member States”
                • Secondary:
                  • CO2MPAS can be used in the “Master Plan for the deployment of Cooperative Intelligent Transport Systems”. In particular CO2MPAS can serve as a reference simulation platform, for testing optimization of transport and logistics system in specific cases [2].

                The model has been already presented to several international conferences and the results from its use published in different scientific journals and JRC reports.

                 

                References: 

                 

                [1] Tsiakmakis, S., Fontaras, G., Cubito, C., Anagnostopoulos, K., Ciuffo, B., 2017. From NEDC to WLTP: effect on the type-approval CO2 emissions of light-duty vehicles (Science for Policy Report No. EUR 28724 EN). https://doi.org/10.2760/93419

                [2] Makridis, M., Mattas, K., Mogno, C., Ciuffo, B., Fontaras, G., 2020. The impact of automation and connectivity on traffic flow and CO2 emissions. A detailed microsimulation study. Atmospheric Environment 226, 117399. https://doi.org/10.1016/j.atmosenv.2020.117399

                Previous use of the model in ex-ante impact assessments of the European Commission

                Use of the model in ex-ante impact assessments since July 2017.

                2017
                SWD/2017/0650 final

                Impact assessment accompanying the document Proposal for a Regulation of the European Parliament and of the Council: setting emission performance standards for new passenger cars and for new light commercial vehicles as part of the Union's integrated approach to reduce CO2 emissions from light-duty vehicles and amending Regulation (EC) No 715/2007 (recast)

                Lead by
                CLIMA
                Run by
                European Commission
                Contribution role
                baseline only
                Contribution details

                Co2mpas was used to calculate the baseline 2015 CO2 emissions from the European fleet of new passenger cars under WLTP conditions.

                Bibliographic references

                Studies that uses the model or its results

                The impact of automation and connectivity on traffic flow and CO2 emissions. A detailed microsimulation study 

                Published in 2020
                Makridis, M., Mattas, K., Mogno, C., Ciuffo, B., & Fontaras, G. (2020). The impact of automation and connectivity on traffic flow and CO2 emissions. A detailed microsimulation study. Atmospheric Environment, 226, 117399. doi:10.1016/j.atmosenv.2020.117399

                How much difference in type-approval CO2 emissions from passenger cars in Europe can be expected from changing to the new test procedure (NEDC vs. WLTP)?  

                Published in 2018
                Pavlovic, J., Ciuffo, B., Fontaras, G., Valverde Morales, V. and Marotta, A., How much difference in type-approval CO2 emissions from passenger cars in Europe can be expected from changing to the new test procedure (NEDC vs. WLTP) , TRANSPORTATION RESEARCH PART A-POLICY AND PRACTICE, ISSN 0965-8564, 111, 2018, p. 136-147, JRC111320.

                A simulation-based methodology for quantifying European passenger car fleet CO2 emissions 

                Published in 2017
                Tsiakmakis S; Fontaras G; Ciuffo B; Samaras Z. A simulation-based methodology for quantifying European passenger car fleet CO2 emissions. APPLIED ENERGY 199; 2017. p. 447-465. JRC106457

                From NEDC to WLTP: effect on the type-approval CO2 emissions of light-duty vehicles 

                Published in 2017
                Tsiakmakis, S., Fontaras, G., Cubito, C., Pavlovic, J., Anagnostopoulos, K. and Ciuffo, B., From NEDC to WLTP: effect on the type-approval CO2 emissions of light-duty vehicles, EUR 28724 EN, Publications Office of the European Union, Luxembourg, 2017, ISBN 978-92-79-71642-3 (pdf),978-92-79-71643-0 (print), doi:10.2760/93419 (online),10.2760/35344 (print), JRC107662.

                Models and scientific tools for regulatory purposes: the case of CO2 emissions from light duty vehicles in Europe 

                Published in 2017
                Ciuffo B and Fontaras G. Models and scientific tools for regulatory purposes: the case of CO2 emissions from light duty vehicles in Europe. ENERGY POLICY 109; 2017. p. 76-81. JRC107225

                Fuel Consumption and CO2 Emissions from Passenger Cars in Europe - Laboratory versus Real-World Emissions 

                Published in 2017
                Fontaras G; Zacharof N; Ciuffo B. Fuel Consumption and CO2 Emissions from Passenger Cars in Europe - Laboratory versus Real-World Emissions. PROGRESS IN ENERGY AND COMBUSTION SCIENCE 60; 2017. p. 97-131. JRC104983

                Introducing a New Emissions Certification Procedure for European Light-Duty Vehicles 

                Published in 2016
                Tsiakmakis, S., Ciuffo, B., Fontaras, G., Anagnostopoulos, K., Arcidiacono, V., Praksova, R., & Marotta, A. (2016). Introducing a New Emissions Certification Procedure for European Light-Duty Vehicles. Transportation Research Record: Journal of the Transportation Research Board, 2572, 66–77. doi:10.3141/2572-08

                The difference between reported and real-world CO2 emissions: How much improvement can be expected by WLTP introduction?  

                Published in 2016
                Fontaras, G., Ciuffo, B., Zacharof, N., Tsiakmakis, S., Marotta, A., Pavlovic, J. and Anagnostopoulos, K., The difference between reported and real-world CO2 emissions: How much improvement can be expected by WLTP introduction , In: World Conference on Transport Research, 10-15 July 2016, Shanghai, World Conference on Transport Research, 2017, ISSN 2352-1465, 25, p. 3933-3943, JRC104702.

                Peer review for model validation

                The application of the CO2MPAS model for vehicle CO2 emissions estimation over real traffic conditions 

                Published in 2020
                Mogno, C., Fontaras, G., Arcidiacono, V., Komnos, D., Pavlovic, J., Ciuffo, B., … Valverde, V. (2020). The application of the CO2MPAS model for vehicle CO2 emissions estimation over real traffic conditions. Transport Policy. doi:10.1016/j.tranpol.2020.01.005

                The effect of electrified mobility on the relationship between traffic conditions and energy consumption 

                Published in 2019
                Fiori, C., Arcidiacono, V., Fontaras, G., Makridis, M., Mattas, K., Marzano, V., … Ciuffo, B. (2019). The effect of electrified mobility on the relationship between traffic conditions and energy consumption. Transportation Research Part D: Transport and Environment, 67, 275–290. doi:10.1016/j.trd.2018.11.018

                The development and validation of a vehicle simulator for the introduction of Worldwide Harmonized test protocol in the European light duty vehicle CO2 certification process 

                Published in 2018
                Fontaras, G., Valverde Morales, V., Arcidiacono, V., Tsiakmakis, S., Anagnostopoulos, K., Komnos, D., Pavlovic, J. and Ciuffo, B., The development and validation of a vehicle simulator for the introduction of Worldwide Harmonized test protocol in the European light duty vehicle CO2 certification process, APPLIED ENERGY, ISSN 0306-2619, 226, 2018, p. 784-796, JRC112017.

                Model documentation

                No references in this category

                Other related documents

                No references in this category