Rolling highway

In North America, the loading gauge is often high enough to accommodate double stack containers, so the height of a semi-trailer on a flatcar is no issue.

However, in Europe, except for purpose built lines such as the Channel Tunnel or the Gotthard Base Tunnel, the loading gauge height is much smaller, and it is necessary to transport the trailers with the tires about 30 cm (11.81 in) above the rails, so the trailers cannot be simply parked on the surface of a flat car above the wagon wheels or bogies.

There is a direct rolling highway between Salzburg and the harbour of Trieste, Italy, where the trucks arrive on ferries from Turkey.

[9] These services are now being extended to other parts of India[10][11] In Switzerland, rolling highways across the Alps exist for both the Gotthard and Lötschberg - Simplon route.

[12] On April 15, 2015, BLS cargo launched a service between Cologne and Milan capable of transporting four-metre (13 ft) articulated lorry trailers.

[13] In 2018, 51% of the Ten-T network has been made adequate to P\C 80 loading gauge, required for ERA Technical Specifications for Interoperability to conveying road trucks by train.

[19] French Transport Minister Jean-Baptiste Djebbari confirmed in September 2021 €15m funding in 2021 for further development of autoroutes ferroviaires including Calais – Sète, Cherbourg – Bayonne and Perpignan – Rungis.