The Stockholm Bypass is a planned new motorway link to the west of Stockholm that will connect Kungens Kurva (E4/E20) in the south and Häggvik (E4) in the north.

Most of the link, about 18km of the 21km route, is planned to run in tunnels with six interchanges linking the surface road network. By connecting the northern and southern parts of Stockholm the route will relieve pressure on Essingeleden and the inner city routes thus reducing the sensitivity of the Stockholm traffic system. At 2009 price levels, the project is estimated to cost £2.6billion. The travel time for the entire route is estimated at 15 minutes.

Construction of the Stockholm Bypass will create conditions for further development in a region that is already growing strongly. It is understood that well developed communications and transport infrastructure are essential for economic development. The project will improve the quality of life for the local population by providing more options to travel by car and public transport and by increasing the freedom to work and live in more convenient locations.

The Stockholm Bypass will also be constructed with great care for the environment, the route of the tunnels ensuring that sensitive cultural areas and important natural environments are maintained.

To put the scale of the Stockholm Bypass into context, it will form one of the longest road tunnels in the world. The ranking will be as follows:

• Lærdal tunnel, Norway 24.50km
• Zhongnanshan tunnel China 18.00km
• St. Gotthard tunnel Switzerland 16.90km
• Stockholm Bypass Sweden 16.50km
• Arlberg tunnel Austria 13.97km
• Hsuehshan tunnel Taiwan 12.94km
• Fréjus tunnel France/Italy 12.90km
• Maijishan tunnel China 12.29km
• Mt. Blanc tunnel France/Italy 11.61km
• Gudvangen tunnel Norway 11.43km

Largest combined length in the world

Although it may not be the longest road tunnel in the world it is the largest with the combined length of the twin mainline tunnels being in excess of 30km (the longest main line tunnel is 16.5km). Add to this access ramps (14km), emergency cross passages (4km) and the access tunnels (3km) and the total length is more than 50km.

Work commenced on the planning and scheme development of the current proposals in 2008, when a team of consultants met with the client Trafikverket to take the project up to and through the statutory processes. On 3rd September 2009 the Swedish government decided to give the motorway project the go-ahead, and invited tenders for the next phase of the scheme development that would lead to the construction phase.

For the tender in 2010, URS formed a joint venture with ÅF AB for the first of two contracts that comprised the Stockholm Bypass. This involved a major interchange at Akalla/Häggvik together with the rock tunnels. The joint venture was successful and as a result the Tunnel contract (FSK02) and the Akalla/ Häggvik Interchange contract (FSK06) were awarded to the URS/ÅF AB joint venture.

The route of the FSK02 element of the E4 Stockholm Bypass starts in the rock tunnels to the north of the Kungens Kurva interchange and involves the underground connection ramps and dedicated bus ramps. It then passes below Lake Mälaren and the island of Lovö, where there is a grade separated underground interchange linking Ekerövägen, (road 261) at Edeby and Tillflykten on the surface. The main line tunnels continue underground from Lovö to Lunda and pass below Lambarfjärden, Grimsta and Vinsta.

At Vinsta, the underground ramps rise to the surface to connect with a new surface interchange, with the main line tunnels continuing underground to Lunda, where they will eventually connect on the surface to another construction contract that will comprise a bridge over the Mälarbanan rail line, Bällstaån/ Spångaån and the E18 Enköpingsvägen. The main line returns underground in a 1.8km long tunnel, under Järvafältet, to a point by the junction of Finlandsgatan and Akallalänken which marks the start of FSK06.

The E4 Stockholm Bypass over the length of FSK02 will be built with two parallel tunnels with the traffic running in one direction in each tunnel. Both the tunnels will have three lanes, with four at the interchanges. At its deepest point, the tunnel will be 60m below the surface of Lake Mälaren and almost 100m below ground.

During construction 6.5million m3 of rock will be excavated from the tunnels. This will be crushed underground and then transported and disposed of in an efficient and environmentally appropriate manner. It will be removed via six access tunnels located at strategic points along the route, in order not to overload the road network with too much heavy transport. Three temporary ports will also be built, one at Sätra and two on the island of Lovö, comprising five jetties in total with a combination of floating and roll on/roll off facilities. The rock mass will be transported between the access tunnel and the temporary port on conveyors. From there it will be transported by water to temporary reception points.

The FSK06 contract comprises the Akalla/Häggvik Interchange, which connects to the rock tunnels via a short concrete tunnel that runs under Järvafältet to Akalla through a deep layer of clay and soft soils. At Akalla, a multilevel interchange will be built in the form of an elliptical roundabout with the Stockholm Bypass running below. The continuation to Häggvik will be through a deep rock cutting, running the entire length of the Hansta nature reserve. At Häggvik the new motorway will join the existing E4 motorway, and will involve the construction of new bridges, concrete underpasses/tunnels and retaining walls, as well as the upgrading of existing structures. At the busiest part of the motorway, twenty lanes will carry in excess of 100,000 vehicles per day, something that will require extensive traffic management during construction. In total, some 2.5km of motorway, six bridges and three concrete tunnels will be formed.

Following the formal start date of 1st September 2011, the project progressed through three different phases: The Planning phase, which involved the handover and interrogation of the existing preliminary design; the Inquiry phase, which allowed supplementary studies and investigations to be undertaken; and the Design phase, which is now underway.

Understanding the Challenges & Objectives

The Stockholm Bypass sets some unique challenges with respect to Building Information Modelling (BIM), and from the outset the client wanted to establish key challenges and objectives that over the full lifecycle of the project will increase efficiencies, enhance data integrity and ultimately reduce risk.

Key BIM Objectives

• Implementation of a Common Data Environment (CDE) for all project stakeholders
• Creation of intelligent, spatially coordinated, 3D models with meta-data, for all disciplines
• Continuous review and mark-up process using the latest 3D review technologies
• Quantities, cost estimation and scheduling driven from an intelligent model base
• Construction ready/as built design documentation driven from an intelligent model base
• Asset management, from design to construction, operations and maintenance. All aspects will be driven using 3D design models with structured object meta-data as the basis

Trafikverket’s BIM Challenges

• Formal verification of model and object’s quality at delivery
• Process for model approval and version management
• Modification and revision of management process
• Status of models and objects
• Meta-data/object properties
• Satellite machine guiding

In the summer of 2011 a series of workshops were held in Stockholm to ensure that a common understanding of the requirements could be achieved.

From these workshops it was quickly recognised that if an “information model” was to be built, and one that would meet the needs of the entire project lifecycle, then a key element would be the implementation of a CDE for all project stakeholders.

Previous phases of the project had produced more than 4,000 documents, and it had been estimated that by the end of the Design phase more than 20,000 documents could exist and that these documents alone would generate more than 500,000 meta-data elements that would need to be managed. In addition, these documents would need to be created, managed and delivered by more than 500 staff from 19 different disciplines in seven different countries, a truly collaborative Pan-European effort.  

Establishing Common Collaborative Practice

For the teams at URS and ÅF AB the implementation of a CDE was seen as the foundation to Building an Information model, and one of the most important elements in meeting the client’s requirements.

Further workshops in Stockholm sought to identify the key ingredients for the CDE and to map out best collaborative practice.

In these discussions URS staff from the United Kingdom highlighted the industry standard collaborative processes identified in BS1192:2007. Many aspects of this Standard were liked by the Swedish team and the client and have now been implemented into the final project solution.

Key Requirements for the Common Data Environment

• Single source of truth
• Common access point for all project design data
• Data available 24/7, irrelevant of location
• Ability to locate and verify data, rapidly and easily
• Ability to geospatially locate documents and CAD models
• Ability to implement client standards for meta-data and document coding
• Language, meta-data had to be programmed to display in Swedish and English
• Implementation of a mandatory approvals process driven by chosen technology
• Compatibility with Microsoft Office, Autodesk & Bentley document formats

The Foundations for Building an Information Model

A key output from the workshops held in 2011 was a BIM strategy report. This report set out the scope for the implementation of BIM based on the client’s requirements and challenges. It also captured the key processes and workflows mapped out during the dynamic and often lively discussions held at the offices of ÅF AB.

Another output from the report was to recommend the adoption of Bentley’s ProjectWise suite of technologies as the preferred foundation for the CDE.

The technology had already been utilised by URS on many major infrastructure projects in the past, such as Crossrail, and was also well known by Trafikverket.

The workshops had allowed the team to assess the requirements, identify potential technologies and make an informed decision on a preferred solution.

ProjectWise provides all project stakeholders with the ability to share a ‘single source of truth’ through a common interface. It also met virtually all of the criteria for a CDE, set out in the workshops, and began to provide answers for many of the client’s key BIM challenges and objectives. Key to the selection of ProjectWise was the ability to locate textual documents and CAD models in a geospatial context.

In addition, the ability to implement custom workflows that performed specific actions on documents, and manage versions as they passed through the approvals workflow was a key contributor to the selection.

ProjectWise also allowed the client’s standard meta-data requirements and document coding to be translated from Swedish into English and displayed through the interface in dual language formats.