Fully autonomous driving is not yet a reality, as it will take several years to develop. However, since 7 July, all new cars will automatically abide by the speed limit of the road they are driving on, and even applying the brakes if the driver continues to exceed it.

Yes, because Intelligent Speed Assist (ISA), the speed limiter designed by the European Commission to reduce accidents and road casualties, is becoming a compulsory piece of safety equipment.

It will have to be fitted by manufacturers on all models presented from July 2022 (without retroactive effect on cars already on the road) and in this in-depth analysis we find out how it works, remembering that it can always be deactivated by the driver.

Speed limiter: how is it made?

To analyse ISA let's start by understanding how it is made.

Already present on several models introduced after July 2022, only as a passive device (i.e. without the possibility of acting independently on the pedals), it is an advanced driving assistant system (ADAS) that combines the information received via the camera for reading road signs (generally positioned on the highest part of the windscreen) with the limits present on the map installed in the native navigators of the infotainment systems.

Thanks to the combination of these two pieces of information, which is necessary to obtain the greatest possible accuracy, the system is able to determine independently which speed limit applies to the road being travelled, displaying it on the car's on-board computer and warning the driver using various methods that we will now reveal.

The camera on the windscreen of the new cars is capable of analysing both roadway lines and traffic signs

How does it work?

How Intelligent Speed Assist works is laid down in great detail by European Union Regulation 2019/2144, legislation that applies directly in all Member States, excluding the UK.

To go into more detail, the lengthy document stipulates that while driving, the system reads the road signs indicating the speed limit at the side of the road via the special camera on the windscreen, comparing the information with the limit on the map on the navigator installed in the vehicle.

After the comparison, which takes just a few seconds, the system provides the driver with the precise speed limit on that road, expecting it to be immediately respected.

However, if the person behind the wheel deliberately chooses to exceed the limit or continues to do so, the system can intervene, firstly with an audible warning or a possible vibration on the steering wheel or seat, and then mechanically, by slowing the car down using the brakes.

Speed limit displayed on the screen in front of the driver

But that's not all. There is a concern regarding the possibility of exceeding the limit of the car "forcing" the restriction.

Control of the vehicle always remains with the driver who, for example, to overtake or merge onto the motorway, can exceed the limits by pressing harder on the accelerator pedal.

How do you deactivate it?

As we have said, even though it is a mandatory device for road safety reasons, Europe has nonetheless given the driver the option of deactivating the system if necessary.

All this can already be done with a few clicks on the car's infotainment system, in particular by accessing the settings relating to ADAS systems, which must however be done every time the car's engine is restarted, as specifically required by Regulation 2019/2144.

Why has it been introduced?

As mentioned, the arrival of this device on cars sold in Europe (along with many other systems) has been promoted to increase road safety, with Europe's main objectives being to reduce road accidents and road casualties by 30%.

But as always, certain doubts remain. The first relates to the possible inaccuracy of the information provided to the driver and the limits mechanically imposed in certain countries, such as Italy, where road signs are often incorrect or not very visible and the information provided on infotainment navigators can vary from one day to the next.

The second is the possible increase, albeit slight, in the prices of new cars, due to higher production costs, given that until now similar systems could be found as an accessory function to some adaptive cruise control systems, for which it was necessary to pay a few hundred euros more when configuring the car.