What are "dragon's teeth" and what do they mean?

Do you know what “dragon’s teeth” are and what they mean? If you live in Madrid, you may have noticed yellow or white triangular markings on the road surface. The point of the triangle points towards the centre of the carriageway, and they alternate with one another. These new road markings are intended to warn drivers that they should exercise extra caution because of a nearby school, care home or even a health centre.

These “dragon’s teeth” are accompanied by other signs that encourage drivers to slow down to 20 kilometres per hour. It is worth mentioning that these road markings are a project of the Ministry of Transport, Mobility and Urban Agenda, which includes them in its standard 8.2. I.C. on Road Markings, in section “9. Special markings to increase road safety”, dated March 2020. In section 9.2 of this draft on the so-called “dragon’s teeth”, we can read:

“These markings may be placed in the section before a stretch where the speed of traffic must be significantly reduced compared with the preceding stretch (for example, when entering a built-up area or urban road), and where drivers must adapt their driving to the new road environment conditions (such as the presence of pedestrians).”

This is what “dragon’s teeth” look like

“The length of the stretch on which the dragon’s teeth are placed will be approximately between 50 and 150 m, taking into account the characteristics of both the infrastructure and the surroundings. As for the geometry of the ‘teeth’, they will be isosceles triangles, with a base of 0.75 m. As for their height, those located in the first third of the stretch will be 0.60 m, those in the following third 0.75 m, and those in the last third 0.90 m.”

In short, the “dragon’s teeth” serve to indicate to drivers the need to exercise extra caution in certain areas. In addition, these markings are not used alone: so-called zigzag edge lines, which form a zigzag pattern and serve to alert drivers to the presence of a pedestrian crossing, have also begun to be used.

Have you seen these signs on the street?