Project Brussels, Belgium

Leopold II Tunnel

Renovation and maintenance of Belgium's longest tunnel.

The 2,600 metres-long Leopold II Tunnel is a major traffic artery of the Brussels Region. With 60,000 vehicles a day travelling along four lanes, it links the northern Belgian motorways to the capital city centre. The obsolescence of the structure called for in-depth renovation: structural repairs, wiring, waterproofing, asbestos removal and a new road deck. The contract also covers maintenance operations for 25 years. CIRCUL 2020, the consortium in charge of the project, consists of BESIX, Jan De Nul and Engie-Fabricom.

Extent of the work

Before renovation work started, the tunnel, built in 1987, presented a certain degree of general degradation, from ceiling to road deck and including the entry and exit ramps.

The contract includes repairs to the structural work, reconstruction of the roadway and surrounds (sidewalks, gutters etc.), technical rooms and 17 emergency exits, as well as asphalting and the general waterproofing of the tunnel. More generally, the tunnel needs to meet current compliance requirements, for example in the area of fire safety.

Before starting work, asbestos had to be removed in an 18,000 m² containment zone.

The specific tunnel equipment also needed replacing, including 800 km of cables, ventilation, communication and surveillance equipment, lighting, etc.
Finally, the interior aesthetics have been totally redesigned.

Work began in May 2018 and will last for 39 months. The CIRCUL 2020 consortium will then maintain the tunnel for 25 years, including equipment replacement and various repairs.

Major technical constraints

Given its location and strategic role, renovation work on the tunnel is carried out exclusively at night, from 10 p.m. to 6 a.m. The July and August school holidays are an exception with the tunnel completely closed.

The tunnel's immediate environment is also particularly dense and constraining, including direct proximity to public transport, in particular a metro line, water table, sewers, and passing under the Brussels-Charleroi Canal, major boulevards and the classified Elisabeth Park.

Work in the tunnel is carried out between 10 pm and 6 am and on working days only. This presents a real and daily logistical challenge with the tunnel needing to be fully operational by 6 a.m.

Bram Vandewalle
Project Manager

Project details

Project name

Leopold II Tunnel


Tunnels, Transportation

Contract type

Design, Build & Maintenance


Brussels, Belgium



Maintenance period

2021 - 2046

Maintenance by

CIRCUL 2020 (Consortium: BESIX, Jan De Nul, Engie-Fabricom)

Renovation period

2018 - 2021

Renovation by

CIRCUL 2020 (Consortium: BESIX, Jan De Nul, Engie-Fabricom)

Total value

€ 500 million

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