Open innovation for Diverging Diamond Interchange (DDI) in Denmark

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This case was submitted as part of the Call for Innovations, an annual partnership initiative between OPSI and the UAE Mohammed Bin Rashid Center for Government Innovation (MBRCGI)

Highway Interchanges are often highly congested. Solving it with traditional measures is costly. With the first Diverging Diamond Interchange (DDI) in Europe, road users change lanes when passing over the highway with fewer conflict points, enabling more capacity, improved safety and less congestion. The Danish DDI has a high return on investment. It was brought to life by an open innovation collaboration between the Danish Road Directorate and the Missouri Department of Transportation.

Innovation Summary

Innovation Overview

Diverging Diamond Interchanges were deployed in the US from 2009 to solve congestion problems in intersections.
The DDI's are unusual in that they require traffic in the intersection to briefly drive on the opposite side of the road from what is customary. By this, road users are ensured a conflict free left turn and increased traffic capacity in all directions. Travel times through DDI intersections are generally 30-40% lower and delays reduced by 70% as compared to other solutions.

The congestion at the intersection TSA 52 in Odense, Denmark had been problematic and unacceptable for several years and had experienced frequent situations with queueing back from the intersection onto the highway. This lead to dangerous situations on the highway that is part of the Scandinavian-Mediterranean Corridor in the European Union. A project to solve the congestion challenge was initiated, but found itself in constraint after it became clear that increased traffic numbers would require a costly extension of the bridge over the highway, thereby exceeding the budget. Unable to find a viable solution in Denmark, the project team decided to scout for new solutions abroad.

A scout-team was sent to the annual meeting of the Transportation Research Board in Washington in January 2015, where it learned about the US experience and know-how from DDI's in operation. Based on the American experience and personal contacts with employees at the Missouri Department of Transportation, The Danish Road Directive decided to initiate a pilot project to test the solution in Odense.

In November 2015, a cross-functional Danish team went on a study trip to the Missouri Department of Transportation to discuss the project design of a DDI at the intersection in Odense. After the study trip, visiting ten DDI's in Kansas City and St. Louis, an iterative process started with workshops, tests and technical assessments towards the construction phase of the intersection. Significantly for the success of the project, several draft versions of the construction project was sent to Missouri Department of Transportation for comments and ideas.
As a result, the first DDI in Europe, at the intersection TSA 52 in Odense, was opened after two years of open innovation between the Danish Road Directorate and the Missouri Department of Transportation.

The main objectives of the project were to design a DDI, while preserving the existing highway bridge and respecting the interests of the local community, close to the project area. A key, technically complex problem of the project was the "crossing over" of traffic to the other side of the road and the "crossing back" to the right lane.

In the design process, the crossing points were enlarged and optimized after literature reviews, interviews with American experts. As a result, the crossing points were moved further away from the bridge, enhancing the capacity of the project and traffic safety, but also increasing the impacts on the landscape. In order to reduce the impacts on the local community, the team decided to adopt a unique, asymmetric design. By this, an entirely new variant of the innovation was invented.

From a traffic safety perspective, key challenges were how to make the road self-explaining and how to make the road users familiar with the design. Here again, literature reviews, interviews and the workshop with US and Danish cross functional teams proved efficient tools for problem-solving and optimization of the project design.

The main benefits of the project are for road users in the local community of Odense and for road users on the highway:

• Reduced queueing back from the intersection to the highway and increased traffic safety
• Increased capacity, especially for traffic crossing the bridge and turning left from the intersection to the highway
• Reduced congestion, resulting in reduced fuel consumption and air pollution
• Reduced travel time by approx. 50% through the intersection
• Reduced construction time
• The DDI in Odense is future-proofed in terms of capacity for the next 15 or more

Thanks to the open innovation, DDI constructions are now part of the Danish toolbox for dealing with congestion at highway intersections.

Innovation Description

Innovation Development

Innovation Reflections

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  • Identifying or Discovering Problems or Opportunities - learning where and how an innovative response is needed
  • Generating Ideas or Designing Solutions - finding and filtering ideas to respond to the problem or opportunity
  • Implementation - making the innovation happen
  • Evaluation - understanding whether the innovative initiative has delivered what was needed
  • Diffusing Lessons - using what was learnt to inform other projects and understanding how the innovation can be applied in other ways

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