Despite all the natural obstacles he encountered, Seguin drew up the plans for line, 56 km in length, with a slow descent towards Lyon.

To avoid difficulties in acquiring land, with no laws concerning compulsory purchase at the time, Seguin built several bridges and tunnels.

[4] In 1835 the proletarian poet Guillaume Roquille published his Franco-Provençal language collection Ballon d'essai d'un jeune poète forézien (Trial balloon of a young Forézien[a] poet) violently attacked the arrival of the railway, which would ruin the canal on which his father worked as a porter.

Where the line descended the horses were carried in a truck for the 22 km descent and then hauled the train for the remainder of journey.

For comfort, the Seguin company had placed drapes on the seats and used leather straps to open and close the windows.

On 3 April 1832, the section up to Lyon was used for freight transport with a few passengers being accepted, who sat on straw in the wagons.

The last section, to Saint-Étienne, was opened on 1 October 1832 for passenger use only, freight being accepted a few months later.