The forecasts have proved accurate, and the figures confirm it: the international Simplon railway corridor has lost considerable ground, with freight traffic declining significantly. Infrastructure works currently under way on both the Italian and Swiss sides are the main cause of the corridor's decline. Moreover, the outlook for the coming years remains bleak, as the works are scheduled to continue in stages until 2029, with closures of varying duration and scope, as well as operating restrictions.
Switzerland's Federal Office of Transport (FOT) has now confirmed with figures what had long been anticipated. In the first half of 2026, capacity utilisation on the Simplon corridor stood at 26.3%, just over a quarter of its theoretical potential, falling further from the already modest 36.9% recorded in the same period of the previous year. The route between Domodossola and Brig has a capacity of 110 freight trains per day, meaning that fewer than 30 trains a day, on average, passed through the historic tunnel during the first half of 2026. In terms of freight volumes, the decline was even more pronounced: approximately 410,000 tonnes of goods were transported along the Simplon corridor in the first six months of 2026, down 15.3% compared with the same period in 2025.
Prolonged maintenance works and the route's less favourable characteristics compared with the Chiasso crossing have created a perfect storm. What is now being seriously called into question is the reliability of this railway corridor. Railway undertakings are finding it difficult to guarantee services, risking their credibility with customers. The logical consequence is a scaling back of operations and future plans, as demonstrated by the drastic decision taken by DB Cargo Italia in 2025 to abandon its Domodossola-Beura facility and concentrate all services on the Gotthard route, despite the site in the Ossola area having been a longstanding base for the Italian subsidiary of German Railways.
Upgrading works on the Simplon corridor began in 2024 under a memorandum of understanding between Italy and Switzerland signed in September 2020 and subsequently formalised through a bilateral agreement in February 2022. Full and partial closures have followed one another over the past few years and are likely to continue until 2029. Construction sites are located both on the Swiss side of the crossing and along the Italian access lines. Swiss Federal Railways is carrying out a complete refurbishment of the historic Simplon Tunnel until 2028, with traffic restrictions for six months each year. The Varzo spiral tunnel, the real weak point of the Simplon railway, will also require refurbishment, although the works will not address its inherent alignment constraints and technical limitations.
On the Italian side, partly thanks to non-repayable funding provided by Switzerland, work continues to upgrade all the tunnels between Gallarate and Domodossola, increasing their loading gauge to allow all types of intermodal trains to pass without profile restrictions and using standard wagons. This is what the Swiss call the "four-metre corridor", enabling semi-trailers with a corner height of four metres and a width of up to 2.60 metres to be transported by rail.
Once the works are completed, trains will be able to depart from Basel and reach transhipment terminals in northern Italy without interruption, particularly Novara and the Milan area, including Busto Arsizio-Gallarate. There are around a dozen tunnels between Gallarate and Domodossola, with a combined length of almost six kilometres. Passing loops are also being upgraded to accommodate 750-metre trains in accordance with European standards. But railway undertakings are asking themselves a crucial question: once the works are finished, we will have an upgraded, high-capacity railway, but will there still be any customers left?
Piermario Curti Sacchi
