One of the main reasons calls 30 CITIES to establish lower speed limits is the road safety, both in terms of accident reduction and the severity of the resulting injuries.
Numerous studies have shown that a speed of 30km/h It is much safer than 50 km/h, especially in areas with high density of vulnerable users, i.e. pedestrians, motorcyclists and cyclists. At lower speeds, drivers have more time to react to unforeseen events, and collisions tend to be less serious.
But why 30km/h? There is three key aspects related to the effect of speed on road safety:
Tunnel Effect: At higher speeds, our vision narrows and we can only process what is right in front of us. This means less ability to react to what is happening on the edges of the road. Lowering the speed from 50 km/h to 30 km/h improves our perception and reduces accidents.
Gravity Effect: Speed also dramatically increases damage in the event of a collision. For example, at 40 km/h the impact is four times greater than at 20 km/h.
Delay Effect: The faster we go, the more distance we need to stop after braking. Reducing speed allows braking in shorter distances, increasing safety.
The figures are serious: according to the World Health Organization (WHO), the risk of death of a pedestrian hit by a vehicle at 30 km/h is approximately 10%, while at 50 km/h the risk increases to 80%.
This speed limitation can ensure survival in the vast majority of cases: it has been proven to reduce the risk of serious injuries by 3% and the risk of accidents with fatalities by 4%.
Reducing the speed limit improves the effectiveness of vehicle safety systems, in addition to considerably reducing the braking distance: at 30 km/h it takes an average of 14 meters to stop a vehicle, while at 50 km/h it will be 30 meters necessary.
As we say, reduced speed limits particularly protect vulnerable road users, such as pedestrians, motorcycles and bicycles. In most cities, school areas, residential areas and shopping centers are places where interaction between vehicles and pedestrians is frequent. By limiting the speed to 30 km/h, you create a safer environment for everyone.
Let us remember that the speed limit of 30 km/h in urban areas applies to streets with one lane in each direction of travel. The main arteries and peripheral rings, which represent the 20% of the streets and support the 80% of the traffic, maintain a limit of 50 km/h.
And beyond road safety, these speed limits have a positive effect on the quality of urban life.
If we talk about decibels, the reduction of traffic noise is one of the most obvious direct benefits. A report from the DKV Institute shows that the noise goes from a 33% at 50 km/h to only a 6% at 30 km/h. Less speed means less engine noise and less noise pollution, contributing to a quieter, more livable environment.
And, in terms of pollution, the emission levels of greenhouse gases can drop between 10% and 15%.
In addition, it has been observed that it contributes to fewer traffic jams and more fluid circulation, since the speeds of cars and cyclists become more equal.
We thus see that the global evidence strongly supports the 30km/h speed limit. With the right focus on education and awareness, cities can take this measure to create safer, healthier and more livable environments for all.
