The project, which has been awarded to the COMOL5 consortium, calls for construction of an expressway connecting the cities of Katwijk (via A44) and Leiden (on A4). On this project, the winning consortium will have to rebuild the motorway junction at Leiden West, build a new 4-km roadway (N434) that includes a 2.2-km tunnel segment, widen motorway sections totalling 12 km in length, and make required adjustments on motorways A4 and A44. The contract also calls for maintenance of the new infrastructure for 15 years.


Construction of the RijnlandRoute is a necessity: it will improve access and traffic flow in the region and stimulate economic growth.
Know-how in achieving major projects is crucial in this densely populated country where there is very limited space for building large-scale infrastructure. Road-construction in the Netherlands requires dealing with canals and residential areas – complex project management issues. VINCI Construction Grands Projets, a longstanding player in the Netherlands has, with its partners, already delivered major projects in this country, including the Pannerdensch Canal, Thalys 4, and, more recently, Coentunnel.


The Comol5 consortium was selected on the basis of its response to various technical challenges, including carrying out work on required new interchanges without interrupting traffic, minimising nuisances, conducting tunnel-boring operations, and managing environment- and traffic-related hazards.
Yet another much-scrutinised challenge involved the quality and solidity of the ground. Since the water table is only 60 cm deep in this area, water seepage and inflow are quite common.
A slurry shield TBM (11 metres in diameter) will be deployed on this project. The tunnel consists of ten emergency galleries, eight of which are located in the TBM-excavated portion and lined with prefabricated ring segments. Artificial ground-freezing technology will be used in the tunnel-boring operations.
The project also includes construction of an aqueduct, which is unusual in such proximity to a bored tunnel, as well as two technical buildings on either side of the tunnel.

 “In the Netherlands, there is a culture of ‘integrated’ projects bringing together design, construction, and systems. This is perfectly in line with VINCI Construction Grands Projets since our own culture is built around this type of project (LGV SEA, Duplex A86, Lusail LRT, and others). We provide a very good fit thanks to this operating model, particularly in projects involving complex structures such as bored tunnels that our Dutch partners have never built.” Sébastien Bliaut, Director, Northern Europe


The project, which includes widening and building roads, will ease the heavy flow of traffic between the cities of Katwijk and Leiden. Motorway A4 (71,000 vehicles a day) will be widened from a dual 3-lane to a dual 4-lane configuration. Motorway A44 (25,000 vehicles a day) will be widened from a dual 2-lane to a dual 3-lane configuration, and emergency lanes will also be added to it.
Project design is complex since it has to deal with densely populated areas with 1,300 inhabitants per square kilometre – the highest population density in the Netherlands. The worksite will cross fields, monuments, decommissioned metal-packaging chemical plants, underwater zones, and old foundations.
Our teams have offered to use the BIM approach for the various project stages, including design for civil engineering tasks, electrical and mechanical work packages, underground networks, and roadworks.
The consortium also plans to use BIM in the maintenance phase (15 years according to the contract) and for the GIS (geographical information system).

Project participants

South Holland region

Project managemet

Key figures

Implementation dates
January 2017 to December 2022

Excavation – earthworks
1.8 million m³

Excavation – tunnel
418,000 m³

Asphalting permanent platforms
437,200 t