Client: Sund og Bælt

Enhancing traffic flow and safety on one of the World’s longest suspension bridges

Safety, Traffic, Transportation

Challenge

The Great Belt Bridge is a critical transport link connecting eastern and western Denmark. Over 11 million vehicles cross the 18 km bridge annually, making it one of the busiest and most strategically important bridges in Europe.

With narrow lanes, high-speed traffic, sudden weather changes and the complexity of digital payment tolls, the bridge presents heightened risks of accidents and traffic disruptions. Even minor driver hesitation or spontaneous behavior—like last-second lane changes near the toll—can trigger unsafe situations.

Sund & Bælt, the organization responsible for operating and maintaining the bridge, wanted to minimize accident risk, improve traffic flow and reduce travel time through a behavior-led redesign of critical traffic environments.

Approach

In partnership med Krukow, Sund & Bælt launched a behavior change program focused on identifying danger zones and optimizing the driving experience.
The work included:

Daily mapping of traffic flows to uncover unsafe patterns.
Behavioral analysis of driver decision points near toll areas and on the bridge.
Design of intuitive interventions to support safe behavior for both passenger cars and heavy vehicles.

Solution – Based on research insights, four core behavioral strategies were developed and implemented:

Clear visual instructions and guides

reducing hesitation by providing timely, intuitive information.

Weather-specific safety instructions

guiding wind-sensitive vehicles off the bridge during storms.

Traffic flow optimization

using behavioral cues to reduce bottlenecks and lane-changing conflicts.

Feedback on traffic and queues

managing driver expectations with early information about toll wait times.

Impact

The behavior-led interventions resulted in:

Smoother traffic flow across the bridge and toll area.
Fewer “near-accident” situations caused by confusion or last-second maneuvers.
Improved driver confidence and reduced stress in challenging weather conditions.

“Optimizing safety and flow at a bridge like the Great Belt Bridge presents challenges due to restrictions and limited opportunities for changes in signage and road layout. The innovative, simple, and effective solutions provided by the behavioral design company exceeded our expectations.”

Bjarne Jørgensen, Executive Director, Asset Management, Sund & Bælt Holding A/S

Conclusion

By embedding behavioral design directly into the traffic environment, Sund & Bælt enhanced both safety and efficiency on the Great Belt Bridge. The project shows how even highly constrained infrastructures can be transformed with low-cost, high-impact nudges—improving the experience and safety of millions of drivers every year.