“Excessive speed has a high presence in accidents and has a direct impact on the severity of the accident,” says Ana Blanco, deputy deputy director of Traffic at the DGT, in statements to the magazine Tráfico y Seguridad Vial. “Fixed speed and average speed controls are very effective in reducing accidents,” adds Blanco to educate about the speed radars that the DGT has deployed on the roads of its jurisdiction.

The reduction in road accidents in Spain is closely related to the greater implementation of radars to control speed on the roads. In 2005 there were nearly 90 radars operational on Spanish roads and currently there are more than 400. In parallel, the numbers of people killed in traffic accidents have gone from 3,841 in 2004 to 1,273 in 2022, that is, two thirds less .

Traffic has 355 radars permanently installed at fixed points where they measure instantaneous speeds and 64 section radars to measure average speeds. The majority of them – approximately 90% – are of the ‘Doppler’ type that emit waves of microwaves against moving vehicles to calculate their speed, and the rest are of the laser type.

In addition to the fixed speed control devices on the roads, there are another 325 mobile radars operated by agents of the Traffic Group of the Civil Guard. They are located at points where there is an accumulation of accidents with victims, normally inside a Benemérita car or camouflaged on a tripod next to the road.

Radars of this type are installed on three different types of supports: gantries on the road, cabins and posts on the sides of the road. As a general rule, the choice of the points where they are located responds to “rigorous studies on accident rates,” explains Ana Blanco. Conventional roads are prioritized as these are the ones that concentrate the greatest number of accidents.

‘Doppler’ radars work through an antenna. They emit a microwave signal that bounces off vehicles traveling on the road and the signal returns to the antenna. The radar calculates the speed of the car at that moment from the frequency of the received wave.

Radars that use laser technology became operational in 2019. They project transverse lines of light towards the road that the moving car interrupts. By ‘cutting’ the light beam, the cinemometer calculates the speed.

The DGT also controls the speed of the cars from the air. It has 11 helicopters equipped with Pegasus radars to complement surveillance on the roads of its competition, especially conventional roads.

When agents patrolling from the air detect a possible offending vehicle, a GPS is responsible for calculating its coordinates based on the position of the helicopter. A laser rangefinder measures the exact distance between the helicopter and the vehicle. With the following locations of the car, the speed of the offender is known.

Unlike other types of speedometers, which measure the speed of vehicles at a fixed point, section radars monitor the average speed of cars between two points. In order not to be ‘hunted’, drivers must maintain an average speed similar to or lower than the maximum allowed during this section.

The operation of the section radars is based on a first laser-LED camera that records the license plate and the time at which each vehicle passes the point where the speed of the cars begins to be measured. Once the car travels the section, a second camera captures the license plate again. The system crosses the data obtained to calculate the time it took the vehicle to travel that distance and obtains the average speed.

All fixed speed cameras on the road are computerized and managed remotely. When one of them chases a vehicle exceeding the speed limit, it automatically generates images and data of the vehicle violation. These data (date, time, location, vehicle speed…) travel in a compressed file to the Automated Complaints Handling Center (CTDA) where the complaint is verified and the sanctioning process begins.