The stark warning came from the state-rail company SNCF’s chief for the Paris region, who said that certain train lines would have to shut completely for several days on end as maintenance work is carried out.
The disruption will be made worse by work on the Grand Paris Express, a new network of suburban rapid transit lines to be built in the greater Paris region which is the French capital’s largest infrastructure project in decades, said Alain Krakovitch, head of the Transilien regional network.
“That means that the next eight years are going to be difficult for our customers, but we will try to make sure that disruptions are kept to a minimum,” he told Le Parisien newspaper.
“We are going into a difficult period because we have a huge amount of work under way, while at the same time having to handle three million passengers a day on the RER and Transilien lines,” said Didier Bense, the director of SNCF Réseau Ile-de-France.
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He said that “intense” work had been carried out to improve the network over the past two years at night or at weekends, when disruption for passengers could be kept to a minimum.
“But that has not been enough. We are going to have to shut down certain lines, sometimes for several days,” said Bense, noting that passenger numbers were projected to increase to up to 4.5 million by 2015.
Pressure to get most of the upgrades done in time for the Paris Olympic Games in 2024 meant that spreading out the work over a longer period, in order to reduce disruption to passengers, was not an option, he said.
The rail officials said the network would do all it could to keep passengers informed of what lines were being affected at any given time and would provide alternative transport, such as buses.
"They've been saying for ten years that they will improve the information they provide (about delays and disruption) , and it has only got worse and worse," said Mr Delarue.