Methodology

Data Usage

Time Period for data
The report strives to utilise the most recent publicly available data and information just prior to the time of publication (as of 30 May 2023). The majority of figures in the report were developed between September and December 2022 using the most recent data available at that time.

Secondary data
SLOCAT relies on secondary data and information collected and provided by SLOCAT partners and other entities and does not make use of any internal modelling tools.

Data on sustainable mobility: A call to action

The report benefits directly from data collected by a wide range of stakeholders working in different areas of transport. 

Data are important for providing a comprehensive picture of the status of sustainable, low carbon transport and are essential for both policy and investment decision making. In these times of change, it is critical to upgrade data and policy collection and interpretation capacities to better understand progress and the hurdles that must be addressed. 

The data limitations mentioned below are not new. Obtaining regular, reliable and public data across regions and transport modes remains an outstanding issue. When an increasing number of stakeholders are collecting data and policy information, more and better open-access data and capacity building efforts for data interpretation are supported by many multi-stakeholder partnerships in the sustainable, low carbon movement. 

If you share our passion for open-access data and knowledge towards greater impact on policy and investment decision making worldwide and/or would like to contribute data or knowledge to our collective efforts on this report, please reach out to the research team in the SLOCAT Secretariat at tcc-gsr@slocatpartnership.org.

Specific data used in this report

Data on emissions

The data in this edition of the report point to the direct carbon emissions from transport activity; they do not cover the indirect emissions and land-use impacts associated with certain modes of transport. The report primarily utilises CO2 emission data compiled in the Emissions Database for Global Atmospheric Research (EDGAR) from the Joint Research Centre of the European Commission, as this represents the most recent, comprehensive dataset on transport CO2 emissions. However, this global dataset does not convey in full detail the unique situations of individual countries.
EDGAR provides estimates for fossil CO2 emissions from all anthropogenic activities with the exception of land use, land-use change, forestry and the large-scale burning of biomass. The main activities covered are CO2 emissions emitted by the power sector (i.e., power and heat generation plants), by other industrial combustion (i.e., combustion for industrial manufacturing and fuel production) and by buildings and other activities such as industrial process emissions, agricultural soils and waste. Transport activities covered within EDGAR include road transport, non-road transport, domestic aviation, and inland waterways on a country level, as well as international aviation and shipping.
For the world, regions and countries, the CO2 emission data (provided by EDGAR) span through 2021. In a few places in the report, CO2 data for 2022 are shown to illustrate the impact of the COVID-19 pandemic; however, these data are based on a different methodology than the EDGAR dataset and should not be compared directly with the data from previous years.
The latest CO2 emission data for individual transport modes as well as passenger and freight transport are for 2019 and have been compiled only at the global level. Data on passenger activity (passenger-kilometres) and freight activity (tonne-kilometres) – provided mainly in the country fact sheets – are based on the latest available year, as indicated in the report analysis.
Information on greenhouse gas emissions – provided in CO2 equivalent (CO2eq) – include not only CO2 but also methane, nitrous oxide, and industrial gases such as hydrofluorocarbons, perfluorocarbons, sulphur hexafluoride and nitrogen trifluoride. These data are less up-to-date. As of 31 May 2021, data on greenhouse gas emissions were not readily available for the period 2019-2020. In some cases, additional data sources were used to provide detailed information about other climate pollutants besides CO2.
All data on CO2 and other greenhouse gas emissions, as well as CO2eq, are provided in metric tonnes.

Data on vehicle fleets

The motorisation rate (as reflected in vehicles per 1,000 people) is based on information by the International Road Federation (IRF)’s World Road Statistics 2022. The indicator “Total Vehicles In Use Rate by Population” by IRF covers all road motor vehicles except motorcycles. The most recent data point between the years 2016 and 2020 have been used to allow global comparisons to a certain degree.

Policy landscape data

Policy-related information presented in this report is mainly focused on 2021 and 2022, with a few exceptional cases and significant developments until May 2023. This information is not intended to be comprehensive. The data for the policy landscape indicators provided in Section 3 were gathered through desk research unless otherwise indicated. Barriers to accessing such information include language and limited availability of information through online media (e.g., websites, press releases and news articles).

Data in country fact sheets

Information in the fact sheets is based on desk research and on contributions from the national focal points. The data were collected to the best of the authors’ knowledge and based on data availability, and thus may not be complete or show the most recent status. When no information is available for a given indicator, the term “Not available” is used.

Data gaps

Major data gaps exist in areas where there is no globally accepted data collection methodology. For example, the mapping of cycling and walking infrastructure is not currently done in all regions. Also, the modal share can be surveyed through different methods, leading to inconsistencies in available data. In addition, data on paratransit (informal transport), a predominant form of transport in many parts of the world, are largely lacking. This results in an incomplete picture of the impact of transport on climate change and sustainable development.

Methodological approach

Countries and regions

The report follows the M49 Standard of the United Nations Statistics Division. In total, 196 countries have official United Nations membership and are also party to the United Nations Framework Convention on Climate Change. The available data have been put in a common structure for the United Nations member countries, regions and income groups to enable a consistent assessment. Income groups are based on the World Bank’s classification of 2022.

Economic calculations

The per capita and gross domestic product (GDP) calculations are based on the United Nations World Population Prospects 2022 and on World Bank GDP data using constant 2015 USD.

Spatial and temporal scales

The geographic scale (global, national, city-level, etc.) as well as time scale (annual, monthly, daily) used in this report depends largely on the available dataset, as noted in the relevant figures and text. The detailed data forming the basis of the calculations and analysis are provided in the SLOCAT Transport Knowledge Base.

Criteria for selection

The report  covers policies, targets, emission reductions (achieved or envisioned) and market measures. To merit inclusion in the analysis, the policies, projects and trends must have been announced or completed between 2021 and 2022. Significant developments from January through May 2023 were included when deemed relevant, with the understanding that the next edition of the SLOCAT Transport, Climate and Sustainability Global Status Report will cover a period starting from mid-2023.

Pre- and post-COVID-19 pandemic trends

The year 2020 was pivotal for the world, and the COVID-19 pandemic has had substantial impacts on many of the transport trends monitored in this report. This edition attempts to differentiate between long-term trends and impacts due to the pandemic. To the extent possible, the analysis notes “pre-pandemic” (up to the end of 2019 or latest by February 2020) and “during pandemic” trends (starting in March 2020 until the end of 2020), as in some cases the pandemic led to reversals in long-term trends, at least for a specific period of time. In each section, a box describes the impacts that the pandemic has had on specific regions and sub-sectors.

Assembling the report

Advisory Team

This edition of the report was guided by a global advisory team consisting of 23 experts in the field who provided inputs over the span of six meetings between April 2022 and September 2023; with ad-hoc support in the months following release to nourish the report’s broader dissemination strategy.

Authors and contributors

The report was collaboratively drafted by over 60 authors and contributors from 33 organisations, led by the SLOCAT Secretariat. This includes additions and high-level inputs from the chief advisor and copyeditor of the report. Authors researched and compiled relevant facts and figures for the five sections of the report, including the Spotlights, with supporting review and inputs from several contributing organisations.

Peer review: A peer review was carried out in April and May 2023 with 650+ comments received from 40+ reviewers. Each comment was individually reviewed by the SLOCAT Secretariat and considered in finalising the report.