Study recommends closing five Brussels road tunnels

A cost-benefit analysis on Brussels tunnels commissioned by Brussels Mobility suggests closing two five car tunnels in the city, which should save as much as €100 million in the long run.

The researchers behind the study said the impact on car traffic flow was small and that public space will benefit, Bruzz reports.

Brussels' car tunnels are of significant importance for traffic flow in the capital, with the Annie Cordy tunnel alone seeing as many as 40,000 cars a day.

And while they allow for conflict-free intersections and sometimes free up public space above ground, tunnel mouths take up a massive amount of space and the tunnels themselves come with high maintenance costs compared to above-ground traffic routes.

There are also drawbacks in terms of limited fall-back options in case of an accident, flooding or fire. In such unforeseen circumstances, the entire traffic grid is immediately jammed.

The upkeep of the well-worn tunnels is also costly: the renovation of the Annie Cordy tunnel, for example, cost as much as €500 million.

The high cost of tunnels is one of the main reasons Brussels Mobility carried out an exploratory study on the future of all 29 of the capital’s tunnels (totalling 12 kilometres) with Stratec and Espaces Mobilités.

The study examined four scenarios for each Brussels car tunnel: a status quo, a tunnel modification, a closure before 2030 and a closure after 2030. Researchers also focused on the financial and social costs and benefits.

For the longest tunnels, the verdict is simple - it is better to keep the tunnels open indefinitely. But the study also suggests closing five shorter and worn-out tunnels in the short term.

The first is two tunnels on Avenue Louise - at Vleurgat and Bailli - which the study said had limited benefit for car traffic, a major impact on public space and crowd out other means of transport.

They are also among the most expensive: closing the Bailli tunnel will save €42.5 million and closing the Vleurgat tunnel another €5.1 million.

“A city boulevard at that location made up of two times two lanes allows bicycle lanes and gains space for pedestrians,” the study added.

Two tunnels could also close on the intermediate ring road: Boileau and Georges Henri. The first tunnel has a major impact on public space, while it avoids only one traffic light. The closure of the Georges Henri tunnel is more complex because of the underlying tram tunnel, meaning a more costly closure of €6.5 million.

The Woluwe tunnel would also be better off closed, the study found, as it is outdated and renovation will be too expensive in the long run, especially compared to its low added value for traffic. Closing it would save the region €15.8 million, researchers said.

In terms of traffic impact, the five tunnels suggested for closure concern only a few minutes on a relatively long stretch of road.

Beyond 2030, researchers suggest closing additional tunnels - Madou, Arts-Loi, Porte de Namur and Avenue de Tervuren (underneath Montgomery) - to save money without sacrificing much in terms of traffic impact.

“In the long term and with the continuation of the Good Move plans and maintaining a large above-ground capacity, closure could be considered,” the study said.

“It is therefore recommended not to invest any more in the tunnel.”

Such investments have already proven tricky: the Brussels region has to pay €650,000 in default interest for unpaid invoices for work on the Leopold II tunnel, now named the Annie Cordy tunnel.

Jan De Mul, the company concerned, invoiced for €175 million worth of work between July 2018 and December 2020 to renovate the Leopold II tunnel, but Brussels was late with its payments amid budget deficits.

“Generally speaking, in the context of public contracts, companies are paid on the basis of debt declarations that are sent for approval by our services by the managing official,” said Camille Thiry, spokesperson for Bruxelles Mobilité, the regional administration for mobility and works.

“Before the invoice is sent and at the end of the contract, especially for large works contracts, we have a final statement of account, sometimes with overruns and additional costs requested by the company compared with what was originally planned. All this has to be examined before payment can be made.”

In the case of the Leopold II tunnel renovations, Thiry said “we're talking about late interest on old cases dating from before 2020. We did indeed have lengthy discussions with the contractors about the final accounts, where numerous checks had to be carried out. We scrutinised everything and there has been interest on late payments for the last five years.”

Brussels Mobility said it had introduced new procedures over the last five years.

“We have introduced centralised management of debt declarations using a monitoring tool,” said Thiry.

“We systematically pay the amounts that are indisputably due. We now only pay any late payment interest on sums where there are discussions or disagreements, without systematically blocking everything, which reduces the overall amount of late payment interest.”