High-speed trains: is rail always better for the environment?

The Grand Pro­jet fer­rovi­aire du Sud-Ouest (GPSO) con­tin­ues to move for­ward despite oppo­si­tion. Work has begun to the south of Bor­deaux with a view to link­ing the cap­i­tal of the Nou­velle-Aquitaine region with Toulouse via a high-speed line (LGV). Ulti­mate­ly, the project will make it pos­si­ble to trav­el from one city to the oth­er in just 1 hour 05 min­utes (1 hour 20 min­utes with stops), but also to link Toulouse to Paris (via Bor­deaux) in around 3 hours 25 min­utes¹ – reduc­ing trav­el times by between 49 min­utes and 56 min­utes. Some envi­ron­men­tal­ists are opposed to this project, even though the train is one of the means of trans­port which is favourable for the envi­ron­men­tal transition.

The train is in fact one of the modes of trans­port to be favoured for the eco­log­i­cal tran­si­tion. A fact that can eas­i­ly be ver­i­fied using ADE­ME’s My trans­port impact tool. The TGV emits 2.93 gCO₂eq per kilo­me­tre, where­as a com­bus­tion engine car emits 218 gCO₂eq, almost 75 times more. A jour­ney from Toulouse to Bor­deaux by TGV, accord­ing to this tool, cor­re­sponds to an emis­sion of 0.77 kgCO₂eq, com­pared with 53.4 kgCO₂eq by car².

So why might envi­ron­men­tal­ists oppose the devel­op­ment of the train? The rea­son is that the way in which emis­sions are cal­cu­lat­ed omits those result­ing from the con­struc­tion of infra​struc​ture​.To reach speeds of up to 320 km/h, for exam­ple, cer­tain con­straints must be met. The lines must avoid exces­sive­ly sharp bends or steep gra­di­ents, lim­it­ing the pos­si­bil­i­ty of bypass­ing nat­ur­al areas, and also means the need for new infra­struc­ture. Hence, it’s not the train as such that’s being chal­lenged, but rather the scale of the works and the eco­log­i­cal and eco­nom­ic con­se­quences that their con­struc­tion will cause. The GPSO there­fore rais­es an essen­tial ques­tion: how is a project of this scale jus­ti­fied in terms of its cost and envi­ron­men­tal impact?

The GPSO rep­re­sents an invest­ment of €14.3 bil­lion³ (esti­mat­ed costs in 2021), of which €10.3 bil­lion will be devot­ed to the Bor­deaux-Toulouse line. A total of 418 km of lines⁴ are to be built between now and 2035 – 252 km to link Bor­deaux and Toulouse, with the remain­der extend­ing the lines to Dax and, even­tu­al­ly, to Spain. A report on the socio-eco­nom­ic assess­ment of pub­lic invest­ment⁵ is used to eval­u­ate such a project in terms of benefits/costs. Patri­cia Perennes, an econ­o­mist spe­cial­is­ing in trans­port and a con­sul­tant with Trans-Mis­sions, has worked for Réseau Fer­ré de France (RFF) and ques­tions this type of assessment.

“The Quinet report does an enor­mous job of syn­the­sis­ing every­thing that is being done in inter­na­tion­al research. It pro­pos­es meth­ods for valu­ing the exter­nal­i­ties of pub­lic invest­ment”, she explains. “For trans­port infra­struc­ture, each exter­nal­i­ty, whether pos­i­tive or neg­a­tive, is con­vert­ed into a mon­e­tary val­ue.” In this way, a sort of bal­ance is formed between the val­ue of the pos­i­tive and that of the neg­a­tive, mak­ing it pos­si­ble to val­i­date an invest­ment project.

“There are exter­nal­i­ties that are sim­pler to val­ue, such as the quan­ti­ty of CO₂ that a project will emit, the cost of its con­struc­tion, or the time it will save,” con­tin­ues the econ­o­mist. “There are also exter­nal­i­ties that can be com­pli­cat­ed to val­ue, such as defor­esta­tion, or the dis­rup­tion of an ecosys­tem. In these cas­es, com­pen­sa­tion mea­sures will be more appro­pri­ate. But plant­i­ng a pine for­est and cut­ting down trees that could be a hun­dred years old is not real­ly the same thing.” In this case, around 4,800 ha of land⁶ are affect­ed – 770 ha for Bor­deaux-Sud Gironde, 2,330 ha for Sud Gironde-Toulouse and 1,700 ha for Sud Gironde-Dax. The impact on bio­di­ver­si­ty, despite com­pen­sato­ry mea­sures, is there­fore undeniable.

An expert report⁷, pro­duced by the École Poly­tech­nique Fédérale de Lau­sanne, assess­es the var­i­ous impacts of this project and the ben­e­fits it will bring, by com­par­ing it with anoth­er so-called ‘opti­mised’ sce­nario, itself pro­duced by RFF. The dif­fer­ence is that the opti­mised sce­nario focus­es on ren­o­va­tion, and there­fore on the use of exist­ing lines. This sce­nario will not bring the same time sav­ings for users – 19 min­utes will be saved com­pared with the cur­rent flow – but it will have a much low­er envi­ron­men­tal impact and cost. The con­clu­sion of this report is quite telling: “The experts were able to note that, faced with impacts of dif­fer­ent kinds, the assess­ment can only be a polit­i­cal one, as it depends on the adop­tion of a sys­tem of val­ues; it is there­fore beyond the com­pe­tence and remit of the experts. The issue is whether to build a new line between Bor­deaux and Toulouse or to upgrade the exist­ing line. This is an emi­nent­ly polit­i­cal issue.”

On the oth­er side of the bal­ance, there are the pos­i­tive exter­nal­i­ties of the project: “For TGV projects, sav­ing time is a key issue,” explains Patri­cia Perennes. “It is also quite expen­sive, espe­cial­ly for pro­fes­sion­als. In 2010, for exam­ple, each hour saved by pro­fes­sion­als in the Île-de-France region was val­ued at €22. And these are the fig­ures for 2010, so with infla­tion it’s bound to have gone up.” Anoth­er impor­tant part of pos­i­tive exter­nal­i­ties is modal shift. It is esti­mat­ed that, through the ‘trans­fer of traf­fic from road and air to rail’, the GPSO would enable ‘a total sav­ing of more than 2.3 mil­lion tonnes of oil equiv­a­lent over 50 years⁸. A sub­stan­tial shift also rep­re­sents a major ben­e­fit in terms of green­house gas emis­sions, giv­en that in 2020 road trans­port account­ed for 94.7% of emis­sions from the trans­port sec­tor, itself the lead­ing source of green­house gas­es in France⁹ (28.7%)[…].

This inter­est in modal shift is also reflect­ed in the free­ing up of exist­ing tracks to give pri­or­i­ty to rail freight in par­tic­u­lar. This argu­ment is also being put for­ward for anoth­er French high-speed rail project that is the sub­ject of much debate. The Lyon-Turin line has also been in the news for years. In his 1998 report, engi­neer Chris­t­ian Brossier wrote that there were 100 goods trains and between 24 and 28 pas­sen­ger trains a day on the exist­ing lines in the Alps. How­ev­er, after numer­ous invest­ments in the region, the num­ber of trains has fall­en year on year, while the num­ber of HGVs using one of the two tun­nels to cross the Alps has remained fair­ly sta­ble¹⁰.

Using data from 1998, a sim­ple cal­cu­la­tion shows the poten­tial of rail for transalpine trans­port in France: assum­ing 100 trains a day, each loaded with 30 con­tain­ers car­ry­ing around 18 tonnes, and run­ning 300 days a year, 16 mil­lion tonnes of goods could be trans­port­ed annu­al­ly. And, as Switzer­land is doing, 2/3 of heavy goods vehi­cles would be tak­en off the road in the North­ern Alps (Fréjus and Mont-Blanc). In com­par­i­son, in 2022, rail’s share of transalpine freight trans­port in France will be just 9.6%, or 2.3 mil­lion tonnes, while 22 mil­lion tonnes will be car­ried by road. These fig­ures high­light the gap between rail’s poten­tial capac­i­ty and its actu­al use. This is why oppo­nents of the projects will tend to favour alter­na­tives that involve work­ing on the oper­a­tion and ren­o­va­tion of exist­ing lines to make the best use of their capac­i­ty. In fact, this is a nation­al ques­tion that has been raised: how is it that Switzer­land, with a net­work of 3,265 km of track, man­ages to run around 15,000 trains a day, while France, with its 27,483 km, only runs a sim­i­lar number?

Final­ly, as Patri­cia Perennes points out: “There is no doubt that if we talk about the flow on these new lines, the eco­log­i­cal impact will be ben­e­fi­cial, but if we take into account the con­struc­tion phase, the cal­cu­la­tion is dif­fer­ent.” And despite the weight of the con­struc­tion phase, the GPSO is still expect­ed to be car­bon neu­tral by 2056. The dilem­ma of our time is embod­ied in this project: rec­on­cil­ing inno­va­tion, effi­cien­cy and envi­ron­men­tal pro­tec­tion is no easy task. 

Pablo Andres