Why not renovate the existing lines?

In order to improve connections in the South West and with Europe, the possibility of renovating and modernising the existing lines between Bordeaux and Toulouse has been studied on several occasions.

The current rail line was opened in 1856. The line follows the course of the Garonne Valley, with numerous curves and level crossings. Between Bordeaux and Toulouse, it passes through around twenty habitat areas in residential areas, including the towns of Langon, La Réole, Marmande, Tonneins, Port-Sainte-Marie, Agen, Moissac and Montauban.
The conclusions are, of course, all the same: it is not possible to run faster trains on the existing line without major and very long-lasting consequences.

If the current line is maintained, the modernisation would save only 10 minutes. By comparison, the maximum time saved on the new line between Bordeaux and Toulouse is 56 minutes.

If more extensive modernisation work were carried out, such as the construction of additional sections of new track, it would be possible to save up to 27 minutes. However, the cost and impact of the work would be much higher. The cost per minute saved would be more than 60% higher than building a new line.

Three modernisation scenarios in detail

Without leaving the current rights of way, the possible time saving is less than 10 minutes. By comparison, the time saving with the new line project is 56 minutes (without the stops at Agen and Montauban) and 49 minutes (with the stops), giving a time saving of three hours, 10 minutes on the Paris-Toulouse route. There is therefore a difference of around 40 to 45 minutes between a new line and an increase in speed on the existing line.
More ambitious scenarios for the existing line involve significant costs (both performance and capacity gains have to be taken into account): the scenarios offering an improvement of 21 or 27 minutes compared to the current situation would require 29 or 50 km of new lines or shunts respectively. In addition, additional tracks would have to be built between Bordeaux–Langon and Montauban–Toulouse (covering a total length of about 30 km) in order to increase capacity.

The table below summarises the results obtained.