Sweden’s capital is alleviating congestion and giving road users more accurate, live traffic information. It all comes down to real-time and historical travel and flow data gathered directly from road users Bluetooth and Wi-Fi devices.
In Stockholm, the most populous city in Scandinavia, the number of cars on the roads is constantly increasing, leading to higher congestion, reduced road accessibility, and increased environmental pollution. In Stockholm County alone, there are over 400 passenger cars per 1,000 inhabitants, a number compounded by occupational vehicles and public transport that also contribute to congested road networks.
To increase travel time transparency, reduce environmental impact and optimise traffic flow, the city realised they needed to have a bird’s-eye view of the traffic network, as well as detailed, up-close analysis of ongoing issues. They also needed a way to act quickly when things start to bottleneck.
After reviewing several systems, Traffic Stockholm found that the best solution for the job was the Veovo queue and travel time measurement solution.
The solution is primarily based on the movement of Bluetooth and Wi-Fi-enabled devices in cars. It provides the city with both real-time and historic traffic information, including detailed statistical information on the travel times, average speeds, dwell times, and movement patterns.
“We use the data for measuring the development in traffic density, speed and congestion,” says Otto Astrand, Traffic Analyst at Trafik Stockholm. “South of Stockholm, where we first installed the solution, will be a roadwork zone for many years ahead, when building the Stockholm Bypass. It will not only affect the main highway (E4) running through the work zone, but also the surrounding roads. With the solution from Veovo we are able to measure the capacity and traffic flow in real-time in and around the area. This allows us to take proactive steps to initiate countermeasures, if traffic build-up should occur. It also helps us to understand various traffic-related matters, such as the impact of traffic control, weather-related patterns, congestion patterns at roadworks, accidents and events, and driving behaviours and patterns. With this information, we can evaluate and validate existing traffic models and make informed decisions about where to prioritise expansions and optimisations to help the daily commute.”
Astrand continues, “Measuring travel times over longer distances in complex traffic environments is complicated to do with our traditional sensors, such as radar and microwave detectors. This solution gives us insights on how much individual journeys can differ from each other, especially when traffic lights are involved. The ability to measure travel times over longer stretches of road, with various queue lengths, and only looking at specific route choices, is another strength of the solution.”
Crowd-sourcing and probe-data services from large, well-known international traffic data providers were unable to provide individual vehicle data over specific distances. Additionally, their licensing restrictions limited data retention and the applications that their data could be used for. A lack of transparency and auditability of those data sources rendered them unsuitable for this specific work.
Johanna Karlsson, CEO of Trafik Stockholm, says: “We are always trying new technologies for traffic monitoring and Veovo complements our other sensors and data sources very well. The ability to measure travel times, monitor queues and perform origin/destination analysis convinced us to adopt the solution for Stockholm. The ability to detect and mitigate disruptive events offers significant economic benefits through reduced travel times and fuel consumption, as well as environmental benefits due to reduced CO2 emissions, and improved air quality.”
The analysed data is also used to display live traffic information on signs around the city.
Otto Astrand explains: “We also use the data to display live travel times via Trafiken.nu, which is our traffic information hub, and on several VMS signs placed around the city. The travel times help road users to make informed decisions about their journey, both in real-time and for those planning their daily commute.”
The travel times are continuously updated, in line with the actual behaviour of road users, so, by considering their route and the time they depart, motorists themselves are helping to reduce bottlenecks and keep traffic moving.
Besides the benefits of real-time reporting, the empirical data is used to detect driving time anomalies. Effectively, this means that the solution can pinpoint road sections and intersections where driving times deviate from the norm as a result of construction projects, incidents, roadwork, faulty traffic lights and other factors. With this information at hand, real-time traffic management can take place.
The data provides a thorough comparison of current vs typical driving times, minute-by-minute throughout the day. The typical driving times, which are continuously updated, are based on various type of days (weekdays, weekend, vacation season or not) and time of day.
If driving times deviate from the typical driving time, the system automatically raises a flag. As the system logs and visualises all deviations, traffic engineers can create historical performance and reliability reports based on deviations from the norm. Managers are provided with an overview of the current situation and tendencies over time, to allow for road improvements and development where needed.
Stockholm joins a host of other major cities, including Bangkok in Thailand, Zurich in Switzerland, Aarhus and Copenhagen in Denmark, Portsmouth and Port of Dover in the UK and most of New Zealand, which use the solution to measure and optimise how road users travel and use the city´s roads.