Traffic jams often come from shock waves that start when someone hits their brakes. The faster the traffic, the bigger the gaps, and the more abrupt the braking. The effect of breaking works its way back down through the traffic, and the many stops have a reinforcing negative effect on the queue, which ultimately causes even more congestion.
One way to reduce traffic shock waves, is to adjust speed limits to delay the onset of congestion and help recover from it. By adjusting speed limits to provide the optimum gap between cars, more cars can get through at any one point.
With the help of real-time traffic data, using Bluetooth/WiFi sensors and radars to measure travel time, speed, occupancy and flow, and looking at past traffic conditions, it is possible to predict congestion. This rapid detection allows road authorities to detect incidents and congestion in a matter of seconds and to take proactive steps to initiate countermeasures, such as adjusting speeds, changing traffic light settings or dispatching traffic regulators.
Multiyear evaluations of Variable Speed Limits (VSL) impact on traffic safety indicate a reduction in accident numbers by as much as 20% to 30% after VSL installation.
The solution works by placing sensors at strategic points along the road. The sensors detect Bluetooth or WiFi devices, found in mobile phones and in-car communication systems. By re-identifying the devices at multiple sensors, travel times, average speeds, dwell times and movement patterns can be measured and calculated.
The collected data can also be used to display queue warnings, travel times and route choices on digital road signs and mobile apps. This live information allows road users to make smarter travel choices and enjoy a stress-free and pleasant travel experience. As the information is continually updated in step with the actual behavior of road users, the motorists themselves are helping to keep the traffic moving.
Studies show that queue warnings reduce speeds and encourage drivers to drive in a uniform fashion, thus preventing congestion and accidents.
Real-time congestion and speed and flow monitoring also allow traffic managers to gain an in-depth insight into the understanding of traffic flows. They also help monitor the development of traffic jams, to proactively manage the road network on a holistic scale, build predictive traffic models and help the daily commute.
Compared to other technologies, such as camera and inductive loops, the combination of measurement with Bluetooth/WiFi and radar provides a more cost effective solution, that is less impacted by wear and tear and weather conditions. It provides more precise and detailed view of the current traffic flow and speed patterns for the individual lanes and road segments.
The main benefits of variable speed limits and displayed travel times, queue warnings and route choices include:
Smoother traffic flows with less stop/starts
More reliable travel times
Fewer traffic collisions
Lower fuel consumption and vehicle emissions
The Bluetooth/WiFi solution mentioned above, named BlipTrack, is successfully employed in optimization efforts in road traffic in Switzerland, Ireland, New Zealand, UK, USA, Canada, Denmark, Sweden and Norway. In addition, the solution is implemented in more than 25 international airports, including Schiphol Airport in Amsterdam, JFK Airport in New York, Toronto Pearson, Dubai, El-Prat Airport in Barcelona, Dulles Airport in Washington, Copenhagen, Oslo, Malpensa and Linate Airports in Milano, Manchester, Brussels, Dublin, San Diego, Helsinki, Auckland, Montreal, Genève, Birmingham, Bristol, Cincinnati, Brussels South Charleroi, Keflavik, Billund and Aalborg. In recent years, the solution has also been rolled out in ports in Denmark and UK, train stations in Holland, ski resorts in USA, amusement parks, and at events all over the world.
Please note that this article expresses the opinions of the author and does not reflect the views of Move Forward.