After years of collecting traffic data based on the movement of drivers´ mobile devices, Aarhus in Denmark has developed a system that can pinpoint any deviation in traffic flow.
Using real-time reporting combined with historical analysis, the city’s system automatically raises a flag if driving times deviate from the ‘typical’ – continuously updated ‘typical’ driving times are based on different locations, days of the week and times of day.
This gives the city a widespread understanding of the impact on traffic of construction projects, roadworks, traffic accidents and faulty traffic lights.
Aarhus is Denmark’s second-largest city and has been using BlipTrack Bluetooth sensors for several years to collect information from the movement of road users´ Bluetooth devices.
Sensors were placed on the entire road network allowing the city to pinpoint road sections and intersections where driving times deviate from the norm.
It can also show the impact the ‘scattering effect’ can have on congestion – the results of the alternative routes motorists choose to take advantage of.
Asbjørn Halskov-Sørensen, ITS project manager at Aarhus Municipality, said: ‘Ultimately, the data contributes to an improved economy and a better environment through reduced driving times and fuel consumption, and thus reductions in greenhouse gas emissions from vehicles.
‘The benefits we have gained from the solution since implementation are very significant. We now discover errors and irregularities that we would not have a chance to see otherwise. In addition, it is extremely educational and easy accessible to study how the incidents of various kinds influence the road network.’
Intersection alarm, analysis and optimisation
Aarhus has around 230 intersections regulated by traffic lights. Aarhus’ Bluetooth sensors measure both short and long distances, as well as the turn flow through intersections and groups of traffic lights in the road network.
As a result, the system can detec tand help resolve a range of problems including:
- Errors caused by incorrect activation of traffic light programs, such as the rush hour program
- Missing or lengthy activation of turn phases
- Defective surveillance systems
- Human error, such as forgetting to switch back to the normal program following maintenance
- Incorrect timing of coordination chains (“green wave”)
The solution is also said to be employed in the UK and across the world.