HAVE you seen them? Strange square road surface marks that are often mistaken for patches of roadworks and seem to appear overnight.
The mysterious square marks can be found almost equally on avenues and streets in the capital of Valencia and they are not pothole repairs, rather something a bit more high tech—modern day technologies to measure traffic.
There are a surprising number of ways available today to count vehicles and measure traffic and one of these is a system that has been implanted in over 3,000 spots in the city and are called loop detectors.
An inductive loop is a square of wire embedded into or under the road. The loop utilizes the principle that a magnetic field introduced near an electrical conductor causes an electrical current to be induced.
In the case of traffic monitoring, the large metal vehicles act as the magnetic field and the inductive loop as the electrical conductor with a device at the roadside to record the signals generated.
The detectors embedded in the roads of Valencia have a dual function, they measure traffic intensity and occupancy time.
With these real-time traffic control detectors in place, the municipality can calculate the number of vehicles on a street and the time it takes for these vehicles to travel on the road in question.
Inductive loop detectors are currently the most widely used devices for vehicle detection.