Hydrogen fuel cell electric vehicles have zero tailpipe emissions. Like battery electric vehicles, their well-to-wheel greenhouse gas emissions depend on the method of energy production. A range of production pathways and technological improvements in hydrogen production are under development, with the potential to significantly reduce greenhouse gas emissions. In 2018, the Department for Transport published the outputs of the Transport Energy Model. The model provides a clear assessment of the relative environmental impacts of a range of fuel and powertrain options for cars, vans, buses and heavy goods vehicles over the period to 2050. This assessment does not distinguish between urban and rural scenarios with regard to the potential for greener transport in rural areas. Network Rail is developing a Traction Decarbonisation Network Strategy that will examine which parts of the network are best suited to use of hydrogen trains, as well as battery and electrification. This will inform Government decisions in 2020.