The so-called Eole project involves constructing an 8km tunnel from St Lazare to Nanterre-la-Folie and upgrading the existing 47km line to Poissy and Mantes-la-Jolie. With funding finalised, major construction is set to begin later this year with RER trains due to reach Nanterre in 2020 and Mantes-la-Jolie in 2022.

Four days later on February 10 French National Railways (SNCF) signed a €186m contract for the rollout of CBTC on the core section of Line E, which will provide capacity for up to 28 trains per hour on the central section of Line E between Nanterre-la-Folie and Rosa Parks. The system - dubbed Nexteo by SNCF - will offer theoretical headways of 108 seconds, compared with 180 seconds at present, enabling Line E to absorb the huge increase in traffic generated by the western extension.

NA AprWhile expansion of the system grabs the headlines, there remains a pressing need to modernise existing RER and Transilien lines and redress the backlog of investment in infrastructure, rolling stock, and stations, which continues to undermine the performance of the network.

The full extent of the challenge facing suburban rail operations in Ile-de-France is exposed in a review of the system and its operation, which was published on February 10 as part of the French Court of Auditors annual report.

A previous report by the Court of Auditors in 2010 noted that recurrent deficiencies in the quality of service on the Transilien network stemmed from "persistent under-investment" over the last 30 years, with funding channelled towards the expansion of the high-speed network at the expense of the existing network, particularly in Ile-de-France. Over the intervening six years, substantial investment has flowed into the network, yet the latest audit found performance of many lines remains below target and is even deteriorating in some cases. Indeed, the auditor forecasts operating performance will deteriorate further before it improves.

The Transilien network makes up only 10% of national system, but accounts for 40% of passenger traffic. Between 2010 and 2014, spending on infrastructure maintenance and enhancements increased from €538m to €810m and is set to increase further over the next few years. However, the average age of track in the core of the network rose by 30% between 2003 and 2014 and 40% of track on the Transilien network is over 30-years-old. Around 15% of electrification equipment is over 80-years-old and 5% has been in service for more than a century. Much of the catenary on RER Line C is over 90-years-old.

The number of speed restrictions has been growing, covering 213km at the start of 2015. The report states that according to managers responsible for maintaining the Transilien network, general infrastructure quality will continue to deteriorate until 2020 and will not recover to current "far from optimal" standards until 2025, with clear implications for safety and performance. Meanwhile, increasing traffic places further strain on ageing infrastructure - passenger-km on the SNCF network rose by 8.26% between 2010 and 2014 and this upward trend continues.

Spending

Under its 2008-2011 contract, SNCF invested €1.35bn in the Transilien and RER networks, while RATP invested e5bn. These sums increased to €2.3bn and €6.5bn respectively in 2012-2015, with a further increase in the 2016-2020 contracts awarded to the two operators by Ile-de-France transport authority Stif last September.

Investment in new rolling stock rose from e200m in 2010 to nearly €300m in 2014. The average age of SNCF's Transilien and RER train fleets fell from 24.6 years in 2009 to 23.4 years by the end of 2014. RATP's fleet of 1589 RER vehicles will have an average age of 18.9 years by the end of this year, compared with 27.1 years in 2011, and 70% of these trains were new or refurbished between 2007 and 2016.

The new operating contracts set more stringent targets for operating performance, although it is questionable whether these are achievable. The 2012-2015 contracts between Stif and SNCF/RATP enforced financial penalties against the operator where punctuality fell below 96% during the peaks and 98% at other times. Between 2010 and 2014, penalties paid by SNCF to Stif for failure to meet punctuality targets trebled from €6.3m to €19.5m.

While RATP has received a bonus for improving performance on the metro, it has been consistently penalised for poor punctuality on RER lines A and B. Since 2010, neither of these lines has achieved the contractual target of 94% of trains arriving within five minutes of schedule. The report notes that for daily travellers on these two lines, which carry nearly four times as much daily traffic as the entire TGV network, hardly a week goes by without a significant delay or cancellation.

Performance on the 11 other RER and Transilien lines operated by SNCF has deteriorated steadily since 2012 and only two lines (H and N) met contractual targets. Passenger satisfaction scores improved on only three lines between 2012 and 2014, remaining static on three lines and declining on seven.

"Peak-hour saturation of lines A and B, delays and cancellations, and traffic -related incidents explain the growing disatisfaction of regular rail users in Ile-de-France," the report states. "This reality must be taken into account in the implementation of the modal shift policy from road to rail. Encouraging the use of public transport over the car is not questionable, but it is necessary to ensure travel conditions meet appropriate standards."

The auditor acknowledges that the operators have achieved improvements in cleanliness, passenger information, and safety, but it suggests more work is still required in these areas.

Grand plans

Paris has an undeniably bold vision for the expansion of its rail network over the next decade. In addition to a string of new tram lines and metro extensions, the €22.6bn Grand Paris orbital express metro network will provide seamless links between the suburbs, major employment centres, new residential developments, and the capital's airports. The Court of Auditors anticipates the cost of implementing Grand Paris will reach €30bn after rolling stock and upgrading existing sections of metro lines 11 and 14 are included, and even this figure could well be "far exceeded."

In addition to capital costs, a much larger network brings inflated operating costs - preliminary estimates indicate that building all of the lines currently proposed could add €1bn to the €5bn annual cost of operating the capital's rail network.

Add all this to the "necessary" cost of bringing the RER and Transilien network up to modern standards, and it's clear Paris and Ile-de-France face a huge long-term financial challenge. According to the report, operating, maintaining and expanding the network will cost €50bn in 2015-2020 alone The auditor questions whether it will be possible to balance the needs of the existing network with the demands of expansion at a time of "high fiscal stress."

The French government's decision to scrap the proposed Ecotax means there is less government funding available for rail projects, and the report argues fares are too low to support investment, a situation exacerbated by the creation a new Navigo fare structure for Ile-de-France. Furthermore, fare evasion is costing the region more than €360m per year in lost revenue.

The court reiterates the recommendation of its previous report in 2010, which called for passengers to meet a higher proportion of infrastructure costs through fares. "The highest priority must be given to improving the existing network because the quality of infrastructure and some rolling stock is not consistent with the demands on the Transilien network."