They are not really new, the Spanish traffic authority DGT began testing their use in 2021, but this summer they are increasingly being seen along the Spanish road network. These are so-called dragon teeth are horizontal traffic signs, i.e., painted along the road with the aim of reducing the speed of traffic.
They get their name from their shape: two rows of triangles along the lane boundaries, giving the impression of being in a jaw. They are placed at village entrances and mark the boundary between the road and the entrance to an urban area. It is the area where drivers should start reducing their speed to comply with locally set speed limits.
Optical operation
The DGT believes that the dragon teeth create an optical sense of constriction on the road which, along with being a new sign, leads drivers to pay attention and encourages them to drive slower. This is one of the new tools used by DGT for this purpose.
Another relatively new system is dashed lines. Spanish emergency service RACE explains that these are lines painted in a regular 30-metre stretch, like a zigzag, and their function is to announce to drivers that they are approaching a pedestrian crossing to slow down.
Supplement to existing facilities
These new traffic signs are complementary to existing speed-reducing devices, such as noise strips. Sound strips are a series of bumps placed at the entrance of villages along a road that produce a sound when a car passes over them to warn drivers to slow down.
Flashing traffic lights that jump to red when they detect that the car is driving faster than the speed limit are also a system used at the entrance of some towns, as are screens that indicate the speed we are driving at before entering the town and warn us if it is above the limit or if it is the correct speed. In addition to these signs, DGT of course also uses other methods to monitor road speed and ‘encourage’ drivers to take their foot off the accelerator, including fixed and mobile radars and other devices such as helicopters and drones.