Programmable Speed Limiter

What is the programmable speed limiter?

The programmable speed limiter is a driver assistance technology that is increasingly common in modern vehicles. Falling into the category of comfort and safety equipment, its main function is simple yet essential: to prevent the driver from unintentionally exceeding a maximum speed they have set themselves. It is a valuable ally for complying with speed limits, whether in town, on the highway, or in specific zones such as construction sites. It should not be confused with cruise control, which maintains a constant speed without requiring any action on the accelerator pedal.

How does the programmable speed limiter work?

Using the speed limiter is generally very intuitive. The driver activates the system via steering wheel controls and sets the maximum speed not to be exceeded using "+" and "-" buttons. This speed is then displayed on the dashboard.

Once activated, the system acts directly on engine management. The driver can accelerate normally until reaching the programmed speed. At this threshold, the accelerator pedal becomes "inactive" and the vehicle gains no more speed. However, the driver retains full control over braking and steering. For critical safety reasons, particularly when overtaking, the system can be overridden. Pushing firmly all the way down on the accelerator pedal (a maneuver known as "kick-down") temporarily deactivates the limit and releases the engine's full power.

The benefits of the programmable speed limiter

The advantages of this equipment are numerous and contribute to a safer and more relaxed driving experience.

• Peace of mind and legal compliance: This is the most obvious benefit. The limiter effectively prevents unintentional speeding, drastically reducing the risk of fines and points on your driver's license.
• Increased safety: By keeping the vehicle within authorized speed ranges, it reduces the risk of accidents related to excessive speed, especially in heavy traffic conditions or poor visibility.
• Driving comfort: The driver no longer needs to constantly monitor their speedometer. This reduction in mental load allows them to focus fully on their surroundings and traffic.
• Fuel savings: By encouraging smoother driving and avoiding unnecessary acceleration, the limiter can contribute to a slight decrease in fuel consumption.

• Speed limiter vs. Cruise control: What is the difference?

It is crucial to clearly distinguish between these two systems, which are often grouped together under the term "cruise control/speed limiter".

• The speed limiter sets a ceiling. The driver must keep their foot on the accelerator to move forward and controls their speed up to this limit.
• The cruise control maintains a chosen constant speed. The driver can then remove their foot from the accelerator, as the car manages maintaining the pace on its own.

Most vehicles today offer both functions, with a button to switch from one to the other.

Towards the Intelligent Speed Limiter (ISA)

The logical evolution of the programmable limiter is the Intelligent Speed Assistance (ISA). This system combines the traditional limiter with a speed limit display system, which uses a camera to read road signs. The vehicle can then automatically suggest that the driver adapt the speed limit to the one read on the sign. Since July 2022, European regulations have actually mandated the presence of this system on all new car models placed on the market. This is an additional step toward semi-autonomous driving, further enhancing safety on our roads.