Another compelling argument of the BESIX tender, besides the attractive price, was its comprehensive quality plan. This approach sets out each step of the project and its impact on the local residents and fauna and flora.
The project was a challenge on many levels. First and foremost, since it is an important and heavily used link, we had to minimize the impact on traffic. By building the second tunnel right next to the old tunnel, we increased the risk of damage and obstacles for passing motorists. In addition, the new tunnel legislation, which was approved shortly after the start of the project, added further safety requirements that we had to incorporate in the design.
As well as renovating the existing tunnel and building a second new one, the project involved (re)building 30 bridges and viaducts. At the same time, the A10 motorway was widened from 4 to 19 lanes over a length of 10 km south of the tunnel.
An important requirement was to minimize the additional traffic inconvenience during the building works. For this reason it was decided to build the second tunnel first and redirect traffic through the new tunnel while renovating the old one.