Center for the Complete Management of Mobility in the City of Granada in English
New warning system on traffic lights
Implementation of new warning system on traffic lights: implementation of red-yellow lights previous to change to green light.
In traffic lights programmation there is always a security time between the pass of green light to another conflicting lighs. These 3 seconds guarantees security in crossroad, both for vehicles and pedestrians, to prevent from accidents if any car or person get in crossroad just before or after the change of traffic lights. Also, duration of yellow light is 3 seconds.
Although, this criteria does not take in consideration that vehicles need some response time, depending on several factors (type of vehicle, age driver, etc) that means between 0,5 and 1,5 seconds: time elapsed between the pass from red to green light and moving off.
This measure that is being implemented by Mobility Area of the City Council in Granada means to show a red-yellow light together on the last two seconds before change to green light, so the driver is ready to move off:
This measure means time saving when moving off which results more efficiency of regulation, shorter waiting periods and lower pollutin emissions. Althought it may seem insignificant, two seconds each phase mean a significant percentage. If one crossroad has 3 phases, it means 6 seconds, this is a 7% of cycle time.
Also, in case of low traffic density, if a vehicle gets closer to traffic light and see red-yellow light, would analyse breaking time and adjust speed to get just when change of color.
This technique is usual in most of european countries and, as far as we know, is not being implemented in Spain. Previously to this implementation, there have been carried out tests months ago, first in a crossroad in Chana district and later in Carretera de la Sierra (four crossroads).
On the week of February 2nd 2026 started the implementation in Severo Ochoa - Méndez Núñez, a process that will be fulfilled on the next days.
Finally, we must point out that this measure is perfectly in keeping with current regulation because yellow light means exactly the same that red light: article 4.2 of General Traffic Rules in paragraph c says: A yellow non blinking light means that vehicles must stop under the same conditions as a red light
Center for the Complete Management of Mobility
Delegation of Citizens Safety and Mobility.
City of Granada
