New studies on transport and the environment have concluded that a Europe-wide underground rail network would bring significant environmental benefits but would strengthen the main cities at the expense of smaller ones.
One of the three studies carried out under a Swiss national research programme found that a Europe-wide underground railway would be at least five times more environmentally friendly than medium-haul air traffic. It said it would also use half as much energy as current high-speed rail networks such as Germany's ICE or the French TGV.
The study was based on plans for a Swiss underground rail network, called Swissmetro. It would involve building two lines along the main routes across Switzerland, from Basel in the north to Lugano in the south, and from Geneva in the southwest, to St Gallen in the northeast.
The main cities along these routes would be connected by magnetic levitation trains, which would achieve top speeds of 500km/h thanks to a partial vacuum in the tunnels.
According to the study carried out by researchers at the federal institutes of technology in Zurich and Lausanne, a similar Europe-wide network would be efficient on distances of up to 1,000 kilometres. That corresponds to a journey from Rome to Frankfurt or Geneva to Madrid.
They concluded that on such distances, the magnetic levitation trains would consume between five and 10 times less energy than aircraft. The underground infrastructure would also considerably reduce noise pollution and alterations to the countryside compared to current rail or air traffic.
However, two other studies done under the same research programme warned that other factors must also be taken into account in an environmental assessment of the projects. These include the way the electricity used to power the trains is produced, and the environmental impact of its construction.
The researchers calculated that the amount of greenhouse gases generated by building the tunnels would equal emissions during the network's first 100 years of operation. Even so, they point out that the aircraft needed to meet a similar demand would generate the same emissions in only 10 years.
Another negative aspect, according to the researchers, is the project's focus on big cities, which would lead to a further marginalisation of smaller urban areas. However, it says the effect on peripheral areas would probably be smaller than that of motorway building or the railway modernisation programme, Rail 2000.
Swissmetro was granted a licence to build a test track in 1997, but its financing remains precarious. The researchers say the futuristic mode of transport is unlikely to be operational before 2030 at the earliest.