THE smart traffic lights they are devices capable of adapting to traffic in real time, reducing congestion, limiting emissions and making daily travel smoother. In cities that have already adopted them, improvements have been observed in the fluidity of vehicular flows, a reduction in unnecessary stops at traffic lights and, consequently, significant energy and environmental savings. The idea behind their operation is, from a conceptual point of view, very simple: instead of operating according to pre-established time intervals as traditional traffic lights do, smart ones they exploit sensors, algorithms and communication networks to automatically modulate the duration of green, yellow and red. This allows us to reduce downtime, prevent traffic jams during rush hours and create sequences of “green waves”, i.e. a synchronization that allows cars to maintain a regular speed without stopping at every intersection. In Italy we are starting to see this technology thanks to pilot projects launched in various cities and the work of companies specializing in intelligent transport systems.
What are smart traffic lights and what are they for
By intelligent traffic light we are referring to a traffic regulation system that integrates sensors and software capable of interpreting in real time what happens at the intersection. Unlike traditional devices, which alternate colors according to a pre-set timerthese systems modulate the duration of the light signal based on the quantity of vehicles approaching or waiting, promoting a more harmonious flow. The objective is twofold: to guarantee greater smoothness and reduce unjustified stops, which represent one of the main causes of fuel waste and the production of emissions.
Going into the technical operation, we note that the update compared to classic traffic lights is profound. Traditional lamps are replaced with high-efficiency LEDs, which ensure greater visibility (even in unfavorable weather conditions) and reduced energy consumption. Traffic lights also become environmental data collection points: some models are able to detect the concentration of substances present in the air, information that flows into dedicated control units for analyzes of environmental quality.
Added to this are sensors that monitor ground vibrations and anomalous inclinations, useful for prevention activities and the study of natural phenomena. However, the most relevant part for traffic management concerns i integrated radars. These sensors can be magnetic, opticians oh ultrasound. The magnetic ones work via a electrified loop placed under the asphalt: the passage of a car alters the generated field, thus signaling the presence of the vehicle to the traffic light center. Optical sensors use cameras or infrared systems to locate the car directly. Ultrasound emits high-frequency sound waves, which bounce off the car body and return to the receiver, indicating the vehicle’s occupation of space. Regardless of how it is collected, all this information is shared with other systems on the network, allowing the system to decide precisely when to give the green light to switch to green and when to maintain red.
What advantages do smart traffic lights offer?
But what are the advantages offered by smart traffic lights? They are different: the overall capacity of the road network increases, public transport can receive priority at critical moments, cycle routes are safer and events that risk creating congestion can be managed through forecasts and simulations. The optimized synchronization allows cars to proceed at a constant speed without constantly stopping, with benefits on both travel times and emissions. And last but not least, the data collected from traffic lights can represent a precious asset for designing more effective mobility policies and for building smarter and more livable cities.
