variable limits at night

Catalonia has discovered variable speed limits. And it is beginning to exploit them to solve problems of different kinds. This alternative to a single and inflexible maximum speed is applied in other European countries but has not taken root in our country. Until now.

The last place to try it is C-31.

Pilot test. For now, it’s an experiment. An interesting examination that may define the future of some other roads in Catalonia. Because, at the moment, it does not seem that the DGT is in the business of applying the measure in the rest of Spain.

Since yesterday, Monday, October 27, drivers have to slow down at a maximum of 70 km/h between 10:00 p.m. and 7:00 a.m. as it passes through Castelldefels (and Gavà). The test aims to verify to what extent the noise impact can be reduced on a road that is very close to the homes in these municipalities.

To do this, two sound level meters have been installed that will collect data along the six kilometers in which the cars have to slow down.

At 70 km/h. As we said, this is the speed at which cars will have to travel at night. The rest of the day, traffic will move at a maximum of between 90 and 100 km/h, the limits that until now were inflexible in this section. That is, whoever maintains the original speed faces a fine of 100 euros without withdrawal of points.

The test is temporary. Next December 4th The usual maximum speeds will be returned and, from then on, drivers will be able to return to their 90-100 km/h. That will be when the data will be analyzed and it will be studied whether it is worth applying new measures.

It is not the first case. According to the DGTapplying variable speed limits can help reduce accidents by 10% but, at the moment, this measure has not been applied in any case. The system is simple, using the road lights, the maximum speed varies up or down.

The system is widely used in Germany. Especially in the famous sections without maximum speed of the Autobahn. And, really, these sections can have a limit. There, the limits may vary depending on the weather, the hours of the day (as in the previous case) or depending on the traffic that is concentrated during peak hours.

This last case is, for example, that of the AP-7. The Generalitat of Catalonia is studying applying sections with variable speed limits to try to reduce the risks due to the increase in traffic registered since the tolls were lifted. It has even been proposed that in some cases a maximum of 60 km/h be maintained.

The noise. It is a problem that has been studied by some institutions for some time. Most of the time it is a problem that is addressed first in the municipalities where the noise of an engine (especially motorcycles) and the sound of music is more problematic than the rolling of the car itself.

However, what is addressed here is the noise generated by the passing of cars. It is estimated that a car traveling at 70 km/h generates 3 dB less on average than a car traveling at 120 km/h. It must be taken into account, however, that the growth is logarithmic and the impact of those 3 dB is much greater in the jump from 77 to 80 dB than in the jump from 17 to 20 dB, to give an example.

In this study It is noted that at night the noise generated by cars is lower because the traffic is also lower. However, the calm at night highlights this noise and, therefore, moving the focus away from the noise (in this case we are talking about an alternative route further away from the neighbors) has a greater impact during the day than at night.

And more impact. Furthermore, beyond the fact that rolling noise is perceived more clearly at night, the WHO also recommends that the noise rates to which we subject our body be lower at night. This is because the impact on rest is greater to the point of recommending that the noise source does not exceed 45 dB.

However, it is estimated that the busiest roads They constantly move between 75 and 80 dB. Figures that put the health of those who live in the surrounding area at risk. In 2021, it was estimated that excess noise had an effect on European income accounts. 147,000 million euros per yearbeing considered the second source of environmental risk for citizens, only behind atmospheric pollution.

Photo | Castelldefels Town Hall and Google Maps

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