This measure would only concern some sections, with specific requirements: for example, having at least three lanes, providing for a mostly straight route and being equipped with speed control tutor systems
According to what has been announced, the government, through the voice of infrastructure minister Matteo Salvini, is evaluating the possibility of raising the speed limit on some motorway sections from 130 km/h to 150 km/h. But, as emerges from the estimates elaborated by Altroconsumo, “the benefits on journey times would be very small compared to the negative impact that this measure could have on fuel consumption, pollution and road safety”.
This measure would only concern some sections, with specific requirements: for example, having at least three lanes, providing for a mostly straight route and being equipped with speed control tutor systems. The amendment could enter into force with the new Highway Code, even if the one now in force already provides for this possibility in certain circumstances – as reported in article 142 – but, to date, no Italian motorway section has applied a speed limit more high, at 150 km/h.
Raising the limit would necessarily lead to an increase in fuel consumption, directly linked to the increase in pollutant emissions. Above 120 km/h – approximately every 10 km/h of speed – approximately 10% more fuel is consumed (a value which may vary according to the characteristics of the car). Going from a speed of 130 km/h to 150 km/h, fuel consumption is 20% higher. For example, a car that consumes 8 liters per 100 kilometers at 130 km/h will consume around 9.7 liters traveling at 150 km/h. Consequently, the increase in consumption would lead to an increase in CO2 emissions directly proportional to fuel consumption, ie 10% more emissions for every 10 km of speed increased. Therefore, traveling at 150 km/h instead of 130 km/h, an increase in CO2 emissions of 20% can be estimated.
Another alarming element is represented by the very negative impact on motorists’ road safety that this measure could have, on some aspects in particular: stopping distance in the event of braking, skidding, vision cone and consequences in the event of an accident. According to Altroconsumo estimates, traveling at 150 km/h instead of 130 km/h requires over 40 meters more to completely stop the vehicle if necessary. It must also be considered that, as the speed increases, the possibility that the car skids and that you can lose control in the event of a quick and abrupt input on the steering wheel increases. On the motorway, such a maneuver may be necessary, for example, when you need to react promptly to an unsignaled and sudden lane change by another driver.
In addition, as speed increases, the so-called “visual cone” of the driver, i.e. his peripheral vision, decreases. It will therefore be more difficult to perceive risks or dangers coming from the side and to react appropriately. Finally, in the event of a motorway accident, the fact that it occurs while traveling at 150 km/h potentially entails greater damage for all the vehicles and people involved: in fact, the kinetic energy of a vehicle traveling at 150 km/h is much greater than that the same vehicle would have traveling at 130 km/h.
The reduction in journey times is the only benefit that should derive from the increase in the speed limit on the motorway. Taking into consideration the example of the A4, on the Milan-Brescia stretch, traveling at 130 km/h the 75 km would be covered in about 34 minutes and 30 seconds; traveling at 150 km/h would instead take around 30 minutes: a saving of only 4 and a half minutes, against much higher costs in terms of environmental impact, road safety and fuel costs.