A2/N2 underpass: final piece in Eindhoven Northwest area development

For 5.5 years Eindhoven Northwest has been working hard to improve the traffic flow and accessibility of the Brainport Industries Campus (BIC), business park GDC Acht and Eindhoven Airport. Both by car, bicycle and public transport. At present, the Municipality of Eindhoven and Strukton, together with partners, are working on the third and final phase, with the new road's underpass under the A2/N2 as a tour de force. Last summer, the 'tunnel legs' were successfully driven in. Together with alderman Stijn Steenbakkers (area development Eindhoven North West and Brainport), project manager Sjaak Gerritsen (Strukton) and project leader Hendrik-Jan Vennix (municipality of Eindhoven) we drove the first metres through the new underpass.

"The municipality of Eindhoven has designated Eindhoven Northwest, like, for example, the Spoorzone area including International KnoopXL, as a strategic development location," begins Steenbakkers. "As alderman, I am responsible for the development of these areas. Eindhoven Northwest is special in that sense, because a number of strategic functions come together here. The airport, GDC Acht and the development of the Brainport Industries Campus (BIC) 1, where various high-tech (manufacturing) companies work together with education under one roof on the economy of tomorrow. In November 2022, the Eindhoven City Council approved the first steps for the expansion of BIC 2, which means that another 225,000 m2 will be added, where the Brainport business community and educational institutions can work on innovative and high-tech solutions for societal challenges in areas such as healthcare, mobility and energy. On the other hand, there is also a lot of eye for greenery and nature development. For example, the Stadsbos crosses Eindhoven Noordwest and in the future we will open the 142-hectare De Wielewaal estate to the public. So with good reason this is a special area, which can also be described as the region from 'chicken to chip'."

According to Vennix, the area development of Eindhoven Northwest represents one of the largest infrastructural expansions since the early 1960s. Steenbakkers adds: "It is important that we invest in the accessibility of our city. This project is crucial for opening up the area and reducing congestion on the A2/N2 and A58, as well as relieving the Anthony Fokkerweg. In addition to car and freight traffic, the area development also focuses on stimulating sustainable transport (e.g. bicycle and public transport). Accessibility is viewed multimodally. The construction of the bicycle bridge over the A2/N2, a bicycle tunnel under the Anthony Fokkerweg in earlier phases and the arrival of HOV3, the third high-grade public transport line in Eindhoven, are good examples of this. The Wegenstructuur Eindhoven Noordwest project is funded by the Ministry of Infrastructure and Water Management, the Province of North Brabant, the Municipality of Eindhoven and the Municipality of Oirschot." 

Strukton is responsible for the execution of the third and final phase, in a construction team with the Municipality of Eindhoven. "The project involves realizing the underpass of a new road under the A2/N2 to the traffic circle at the GDC Acht business park," Gerritsen says. "Although the call for tenders 'included' a reference design of the underpass, it did offer the opportunity to come up with an alternative. We redirected the original plan from a wall/roof method to driving in precast elements. With this nuisance-driven incentive, we were awarded the project. Then, by also phasing smartly, two-way traffic across the A2 always remained possible." To this end, Strukton set up construction sites on both the west and east sides of the A2/N2 and prebuilt two tunnel slots there. "The four slots were between 21 and almost 30 meters long, all 12 meters wide and weighed around 1,300 to 1,900 tons," Vennix knows. "In the middle of the summer vacation of 2022, the tunnel sections were driven in."

Entering the four tunnel sections was definitely the technical highlight of the project. "First, the capacity on the A2/N2 was halved in a temporary traffic system, with half of the total 15 lanes remaining open in both directions for 3.5 weeks during the work," Gerritsen explained. "Then on the west side we started breaking up the national highway and excavating the alignment to receive the two tunnel legs. The ramp was provided with a sand-by-sand bed, leveled and leveled to drive both sections down successively on a platform of SPMTs and move them into position. A precision job, as the SPMT was incapable of moving the high weight backwards (read: uphill)." In eight days (24 hours a day, with a team of 100 people), the job was completed and everything was replenished to allow traffic to move over the first two tunnel legs. Then it was the east side's turn. "The same work, but in mirror image. And we had an extra day," Gerritsen says. "The most exciting moment in this phase was, of course, the 'fitting' of the third tunnel leg. Here, too, we could not move backwards with the SPMT. Fortunately, those 'worries' turned out to be unfounded, because it fit like a glove."

By deviating from the reference design, traffic experienced only 3.5 weeks of some disruption to the construction of the underpass. "A huge difference from the initial method, which would have required setting up a temporary traffic system for over a year," says Vennix. "That phasing, by the way, was preceded by an intensive preparation process. On the one hand to inform the environment and stakeholders, but also to 'reach' the vacation traffic and divert it in time. The 60-minute delay, as calculated in our models and communicated to the 'outside world' as a possible expectation, did not occur." Steenbakkers: "It deserves a big compliment to all parties involved. We were a little tense about the effect of partially closing one of the Netherlands' most important main arteries in the middle of the summer vacations. But it all went smoothly and also ahead of schedule. Traffic was hardly affected at all. Real craftsmanship."

Currently, Strukton is finishing the underpass and building the road construction. The road will be connected to the existing traffic circle at the GDC Acht business park. This will create a better connection with the slip roads to the A58 in Best and make the business park less dependent on the A2/N2 alone. The underpass of the A2/N2 and thus the final completion of the third and final phase of the road infrastructure in Eindhoven Northwest is expected to be officially opened at the end of September next.