Estimation of the energy consumption and GHG emission of a public rail transport system in France combining tramways and metros for daily commuting

The transport sector is a major source of greenhouse gas emissions, and internal combustion engine vehicles are responsible for a large proportion of these emissions. The use of public transport instead of thermal vehicles should be encouraged wherever possible, particularly in urban areas, to reduce environmental impacts. However, the public transport system is generally multimodal, and consists of a combination of several means of transport such as subways, tramways, trains, buses, bicycles, etc. The combination of different modes of transport needs to be studied in terms of greenhouse gas emissions and energy consumption. This paper focuses on the study of a daily commute combining tramway and subway. The urban area considered is the European metropolis of Lille (France). For the considered home-to-work journey, using public transport instead of a gasoline car reduces greenhouse gas emissions by more than 100 times, despite a 50% increase in journey time.