What was the A2 like before the entire project began?

Nowadays the old church villages at both sites of the A2 got too small. Not every neighbourhood can have its own school, church and shopping centre.

Neighbourhoods must work together on a larger scale, but the barrier formed by the A2 makes that impossible. Pedestrians and cyclists in particular have – in a matter of speaking- to risk their lives trying to get to the other side of the street...

So looking at the city, the A2 highway runs on two times two lanes through the eastern part of the city of Maastricht. What the city wants most is a solution to a persistent problem that splits the city in two: the A2 national highway. Maastricht longs for change, connection, cleaner air, and a reduction of noise pollution. 

We want to restore both the east-west and north-south connections, connect the city to the Country Estate zone (Landgoederenzone) in the north, and bring the neighbourhoods in Maastricht East closer together.

What prompted the city to transform the A2 highway? Why did it need to be changed?

Since 2003, four cooperating government partners have been working together to create a joint action plan.
The Directorate-General for Public Works and Water Management, the municipal council of Maastricht, the provincial government of Limburg and the municipal council of Meerssen founded their own project agency to work quickly and efficiently. 

Before the partnership, A2 Maastricht was primarily viewed as a traffic problem; the congestion on the national road leading through the city needed to be improved. They could not allow the economy to suffer from the impending poor accessibility.

However, the government bodies gradually came to the conclusion that it was not just a question of infrastructure.

The aims became extensive:
  • improve the accessibility of Maastricht and create good traffic flow along the A2
  • increase road safety and quality of life (liveability) in the surrounding areas
  • create new urban opportunities for neighbourhoods along the A2 and remove the A2 barrier 
The government partners decided early on that a tunnel under the city would be the best solution. This avoided the need to create a ring-road around the city which would have had to use greenbelt land. Simultaneously, the financial viability for a tunnel increased as the government bodies brought together the necessary total budget upfront.

It was also decided that an innovative procedural approach would be taken. The aims, budget, and approach were contractually established. 

Why is the A2 highway so important?

The A2 is a major international connection between Amsterdam and Southern Europe. And the A2 is an important link for the city and region of South Limburg. But ... people also need a safe and healthy environment.

How many people on average use the A2 highway on a daily basis?

Around 45.000 vehicles per each 24 hours travel take that highway. When nothing is done this will increases to 75.000 vehicles per 24 hours in 2026. This will have enormous consequences not only for traffic but also for the neighborhoods. 

What problem had to be solved? What is the overall concept of the project?

Mission to the construction companies: 
  • improve the accessibility of Maastricht and create a good traffic flow along the A2
  • increase road safety and quality of life (liveability) in adjacent areas
  • create new opportunities for neighbourhoods along the A2 through urban renewal and the removal of the A2 barrier 
In other words: 
"produce an integrated regional design; a single, all-encompassing plan for the city and the new motorway, and surprise us with solutions that we could not have thought of ourselves."

How large is this project?

Integrated regional design:

1. Infrastructure
Among others:
  • A2 Tunnel
  • city boulevard at ground level
Overall: 21 constructions are being built for A2 Maastricht.

2. Innovative approach
Opportunities for the direct area (vicinity)

Among others:
  • removal of barrier
  • urban renewal
  • environmental quality
  • improvement of networks
3. Property development
  • 1100 new homes
  • 30,000 m2 commercial space
  • additional property potential

How much is this project costing overall?

The project involves an investment of approximately one billion euros, 850 million of which are being provided by the public sector.

How large is the team that is involved in executing this project?

The government partners' project agency currently has a staff of more than 50, and the contractor has around 500 people working on the project.

What are we hoping to achieve from this project?

To improve the accessibility of Maastricht and create a good traffic flow along the A2.
But above all we want to restore both the east-west and north-south connections, to connect the city to the Country Estate zone (Landgoederenzone) in the north, and to bring the neighbourhoods in Maastricht East closer together.

What is the impact this project has on the city?

A project as ambitious as the ‘Green Carpet’ project will inevitably have a major impact on the surrounding area. The city first had to get used to the idea that such a radical change was necessary. We then demonstrated to the local residents the benefits of the chosen plan. They were then given the opportunity to respond to the plan. 

The local residents are now seeing the work take place, sometimes directly outside their front door or a few streets away. The work began in 2010 and will the tunnel will be finished in 2016. Motorists must follow road diversions, which are working very well. After 2016 work will start on the redevelopment above-ground.

Time schedule
  • Plan preparations 2003 to 2006
  • Procedures 2006 to 2011
  • Choice of best plan 2009
  • Start of preparatory work 2010
  • Start of large tasks 2011
  • Tunnel in operation 2016
  • Project completion 2016-2026 
The vision; the entire design process 
The 'Groene Loper' -Green Carpet- plan was chosen in 2009 as the best plan for A2 Maastricht. This plan was devised after a 2 year tender procedure in competition by Avenue2, a building consortium formed by Ballast Nedam and Strukton, 2 main contractors in The Netherlands.

Their vision on the Design & Construct project:
  • A corridor through the city with three different uses.
  • Design of a dual-layer tunnel with two layers of two tunnel tubes. 
A total of eight lanes that are suitable for much more traffic than is currently possible (according to calculations) has been deemed necessary. Originally there were only going to be six lanes.
  • The dual-layer tunnel takes up less room than a traditional (proposed by the public parties) two times three  motorway. 
  • This results in more space above ground to create a new part of the city next to the tunnel. It is forbidden to build on top of the tunnel.
Dual-layer tunnel Park avenue
The core of the plan is:
  • The layered tunnel that will take 80% of the current traffic underground, and a residential area above ground. 
  • A new green, recreational ribbon for cyclists and pedestrians - the Groene Loper (Green Carpet) - that will run from the south to the far north of the city.
  • Above the tunnel, there will be a tree-lined park avenue for pedestrians and cyclists which 'pushes' – so to speak-  the cars to the sides. The park avenue is part of the Green Carpet. Cars (local traffic) will still be allowed onto this road within the city. Once beyond the north of the city, the Green Carpet will only be for pedestrians and cyclists.
  • The park avenue will help the neighbourhoods around the A2 to grow towards each other, making the city a whole again. 
The results so far
The opening of the tunnel is planned for the end of 2016. The creation of the Groene Loper and the park avenue will commence in 2017. The new properties will be built between 2016 and 2017. 

The structural shell of the tunnel will be finished by the end of 2014. The fitting out of the tunnel and the installation of (safety) equipment is planned for 2015 and 2016. 

21 constructions are being built for A2 Maastricht. Fifteen of these have already been built and six are still under construction. 
Permanent constructions
  1. Railway viaduct, part of the new connecting road to the Beatrixhaven industrial estate
  2. Beukenlaan tunnel for cyclists and pedestrians, part of the new connection route to the Beatrixhaven industrial estate
  3. Mariënwaard viaduct, part of the new connecting road to the Beatrixhaven industrial estate
  4. Eco-culvert for wildlife on the connecting road to Beatrixhaven
  5. Kalverbosch and Bunderbosch; two ecoducts for wildlife
  6. Expansion of existing viaduct at Kruisdonk junction
  7. Noise barrier at Amby
  8. Lengthening of Severensstraat tunnel
  9. Bridge for pedestrians and cyclists on the ‘Green Carpet’ in direction of country estate zone
  10. Noise barrier at Kruisdonk (Rothem)
  11. Flyover junction A2/A79 Kruisdonk
  12. Underpass for stream (the Kanjel) under A2 at Tapgraaf junction
  13. Eco-culvert for wildlife under A2
  14. Two viaducts on A2 improving access to Beatrixhaven
  15. Expansion of existing Ambyerweg viaduct with new bridge for cyclists
  16. New flyover Viaductweg South
  17. New flyover Viaductweg North
  18. Cycle tunnel Geusselt
  19. Small-scale tunnel; ‘Green Carpet’ route for pedestrians and cyclists in direction of country estate area
  20. Flyover Europaplein
  21. Dual-layer tunnel
The complex engineering
Although the shape of the tunnel is innovative, the construction technique is not new. The technique was applied because of several challenges that Avenue2 had to overcome in this project.
  1. The aim was to design the best solution for both city and highway while adhering to the fixed budget. Avenue2 decided that a stacked tunnel between the junctions combined with a longer tunnel would best meet this goal. It was therefore necessary to use a building method that would be financial feasible per meter and also minimize any risks. It was determined that the “cut-and-cover” technique would be the best solution. 
  2. However, Dutch contractors are used to working with soft soil, which is not found in Maastricht. The subsoil is totally different from what is found elsewhere in the Netherlands. The top 2 or 3 meters consist of a soft, soil-like clay mixed with sand and peat, but beneath that is a 7 or 8 meter layer of course gravel with large boulders, followed by a thick layer of both strong and weak limestone, small caverns, and zones of flint (a very hard material). In order to build a construction pit for the cut-and-cover tunnel, the engineers called upon the expertise of colleagues in Germany, Belgium, and France. The diaphragm technique was used to dig 25 meter deep trenches, which were kept open with a cement–bentonite fluid, in order to lower in sheet pile walls. After hardening, lowering the groundwater table, and installing stele beams between the sheet pile walls, a construction pit 2,300 meters long, 30 meters wide, and 17 meters deep was built. An investigation of the limestone, however, produced a wide range of results. In order to avoid having to build an over-dimensioned construction pit, it was decided to use the observational method during digging to monitor the process and take any required measures. The construction pit was therefore created in a controlled manner. 
  3. The construction work was divided into five phases, namely pouring the concrete for 1) the floor, 2) the lower tunnel walls, 3) the intermediate floor, 4) the upper tunnel walls, and 5) the roof. In between each phase, the concrete needed to harden. Two “trains” of tunnel construction – one from south to north, the other from north to south – ran beneath the city, constructing 48 meters of tunnel every week. The concrete works started at the beginning of 2012 and ended just before Christmas 2014. The main challenges in this period were logistics and handling the equipment and materials. As only a small access road on one side of the construction pit was available, it was very hard for the logistics manager to supply all the materials on time. 
  4. Another challenge in the design and during construction was that the project could not hinder the traffic: All four lanes of the A2 highway, which is situated exactly where the tunnel was to be built, had to remain useable during the construction work. This meant fitting a temporary road into the already very small building site. This was not possible at the center of the site, because of two nearby apartment blocks. There was simply not enough space to squeeze in the temporary road and the construction pit. The solution was to build 170 meters of a “walls and roof” construction to allow the traffic to keep flowing while underneath it the work continued. 
  5. Besides the concrete works, special attention was also paid to the safety installations in the tunnel. During the design phase, the legal requirements were changed in the Netherlands to bring them into line with European regulations. The concrete works were sped up, allowing more time for the installation of the safety equipment and thus keeping the project on track for its scheduled opening in December 2016. 
  6. Building in a residential area with people living very close to the construction site – sometimes only a couple of meters away from it – requires project managers to pay special attention to the various forms of unavoidable nuisance. Keeping the residents informed and persuading them to be proud of the tunnel construction was one of the most important challenges. Very intensive communications on several levels were started years before the actual construction began. These communications concerned not only the technical issues, but also the new residential area that was to be built. The latter received the most focus, because re-creating a livable city center was even more important than building a tunnel.