Community of Metros

The Community of Metros Benchmarking Group (COMET), formerly CoMET and Nova groups, is a multinational collection of metro systems focusing on international benchmarking, facilitated by the Transport Strategy Centre (TSC) at Imperial College London. The Community of Metros consist of 47 metro systems in 44 cities around the world. The groups are jointly owned and steered by the various members.

History

In 1994, London Underground and four other metro systems formed a small group to share performance data with each other. In 1996, the Community of Metros (CoMET) group was formed with 8 metro systems, to allow benchmarking between them.^[1]

COMET benchmarking

The four main objectives of the metro benchmarking groups are:^[2]

To share knowledge and identify best practices in a confidential environment
To support members in achieving their operational and strategic goals – focusing on improvements
To build systems of measures for use by management and to establish public transport best practices
To prioritise areas for improvement and support decision-making for management, boards, government, and other stakeholders

The key performance indicator (KPI) system is used by the COMET during the benchmarking process in order to compare performance across the member metro systems. The purpose of benchmarking is to search for best practices that lead to superior performance. There are approximately 30 top-level indicators, which are designed to measure the overall performance of the organisation in six distinct areas:^[3]

Growth, learning, and innovation
Financial
Customer
Internal processes
Safety and security
Environment

The indicators are reviewed by members on an annual basis. The group members operate under a full confidentiality agreement. This allows for full data and information exchange within the COMET but not externally.^[4]

Statistical analyses are used to provide greater understanding of the results, while time series analyses allow for trends in performance to be identified. This helps to highlight which members are changing their practices and what improvements are relatively achievable. Where clear differences or improvements in performance are identified, detailed analysis is carried out through case studies.^[5] Multiple case studies are conducted in the COMET each year; these studies include detailed data analysis, questionnaires, and interviews with functional experts. Case studies are further supported by expert workshops where appropriate. In many cases, best practices may be found outside the metro industry, so other public transport operations and even other industries are reviewed for relevant practices.^[6]^[7]

Membership

As of August 2025^[update] the Community of Metros consisted of 47 metro systems located in 44 cities around the world.^[8]

Former members

Moscow Metro (membership ceased in March 2022 due to military invasion ^{[citation needed]})
Sydney Trains (joined International Suburban Rail Benchmarking Group (ISBeRG) in 2011, and terminated its parallel CoMET membership in 2024)

Major publications

Some of the major publication journals by COMET include:

Canavan S, Barron A, Cohen J, Graham DJ, Anderson RJ et al. (2019). Best Practices in Operating High Frequency Metro Services, Transportation Research Record.
Anupriya A, Graham D, Anderson R, Carbo JM et al. (2018). Cost Function for Urban Rail Transport Systems, Transportation Research Board 98th Annual Meeting.
Canavan, S., Graham, D.J., Anderson, R.J., Barron, A. (2017). Urban Metro Rail Demand: Evidence from Dynamic Generalised Method of Moments (GMM) Estimates using Panel Data.
Hörcher, D., Graham, D. J., and Anderson, R. J. (2017). Crowding cost estimation with large scale smart card and vehicle location data. TRANSPORTATION RESEARCH PART B: METHODOLOGICAL, 95, 105–125.
Singh, R., Graham, D.J., Anderson, R. (2017) Characterising journey time performance on urban metro systems. TransitData conference, Santiago, Chile, 22 May 2017.
Hörcher,D., Graham,D.J., Anderson,R., (2017) Crowding cost estimation with large scale smart card and vehicle location data, Transportation Research Part B: Methodological, pp. 105–125.
Brage-Ardao, R., Graham, D.J., Anderson, R.J., Barron, A. (2017). Metro Operating Costs: Main Patterns and Determinants. Transportation Research Board 96th Annual Meeting.