The city of Aarhus, Denmark has deployed 10 dynamic digital signs that are driven by motorist’s Bluetooth equipment. The signs provide instructions that include driving times and the fastest routes, which saves time and helps traffic flow smoothly.

In Aarhus, as in other large cities facing substantial challenges with traffic congestion, yet another means has been adopted to attempt to smooth the traffic flow and provide motorists with faster journeys. Ten dynamic signs, provided by ITS Teknik, featuring information such as driving times, alternative routes and weather conditions have been placed along the city's busiest roads. The content of the signs is updated on an ongoing basis as the actual characteristics of the traffic flow change. The motorists themselves, by contemplating the routes and points in time when they drive them, contribute to improving the level of service and helping the traffic move faster.


“The messages on the signs have been developed and adapted based on studies of commuters, and hence reflect information that the target group both demands and respects. The dynamic signs will be of benefit to the motorists, who will experience a higher level of service, and to the flow of traffic in general," says Claus Pedersen, Head of the Centre for City Use.

BlipTrack-Traffic-IllustrationMotorists provide traffic data
The traffic data on the new information signs is based upon real-time inputs from 125 sensors that are placed on selected roads in Aarhus. These sensors detect motorists driving with a Bluetooth device, such as in hands-free systems and mobile phones. When a vehicle with an activated Bluetooth device passes the sensors, its anonymous ID, also called a MAC address, is recorded, encrypted and time-stamped. The data is then sent to a server where it is filtered and analysed.

By combining the data collected by all sensors, an accurate picture about each road user, such as their travel times, dwell times and movement patterns are provided. The information of the monitoring system are used to inform and warn city traffic engineers about queues and delays, identify problem areas, evaluate and calibrate traffic signals, provide information on the capacity of existing roads, and detect changes in traffic patterns.