Modern cars are increasingly equipped with advanced technologies to improve driving safety and driver comfort. One such solution is the Traffic Sign Recognition System (TSR - Traffic Sign Recognition). Its task is to assist the driver in complying with traffic regulations and to warn of applicable speed limits or prohibitions. How exactly does the sign recognition system work? How does it detect traffic signs? Is it reliable? And why do some drivers choose to switch it off? Let's find out.

What is traffic sign recognition (TSR)?

TSR system is one of the elements advanced driver assistance systems (ADAS). Its main task is to identify vertical signs, mainly speed limit signs, overtaking bansand sometimes warning signs or information.

Recognised signs are displayed on the instrument panel, dashboard or head-up display. Sometimes it also appears warning audible or graphic if the driver does not react to excessive speed, for example.

How does the TSR system work?

The system is based on camera mounted behind the rear-view mirror or at windscreen. This camera monitors the surroundings and records the signs visible on the road. The image is then processed by the on-board computer, which recognises the content of the signs.

In more advanced versions, the system also uses GPS navigation data and digital maps, making it possible to correct recognised signs or display speed limits, even if the physical sign has not yet been detected by the camera.

Character recognition system functions

The TSR system in modern cars offers a number of practical functions:

• recognises speed limit signs, Overtaking bansand the end of bans,
• alerts the driverwhen exceeding the speed limit,
• cooperates with active cruise control (ACC), automatically adapting speed to regulations,
• announces a change in restrictions on head-up display or dashboard,
• can interact with the video recording system (video recorders), recording infringements by the driver.

What characters does the system recognise?

A typical sign recognition system can detect:

• speed limit signse.g. 30, 50, 90 km/h,
• Overtaking bans and their appeals,
• warning signs (e.g. slippery pavement, roadworks),
• information signssuch as a residential zone.

In some car models of the class top shelfThese systems can even analyse temporary markings, e.g. during road repairs.

Is the system working properly?

Operation of the system is generally reliable, but in practice much depends on external conditions:

• when it comes to heavy rainfall or snow, the camera may have a reading problem,
• dirty windscreen or the camera may interfere with the operation of the system,
• illegible or displaced characters may mislead the system,
• temporary road signs (e.g. from paper, on renovations) are often not recognised,
• action may vary depending on car manufacturer.

Mandatory equipment or add-on?

For many car models sold in the EU, sign recognition system has become mandatory equipment from 2022. In older cars it was available as an option or as part of ADAS packages. In each case, its purpose is to increased security on the road and driver assistance in driving.

Disadvantages and problems with the TSR system

Despite their many advantages, character recognition systems also have their defects. The most common of these are:

• false sign readings or failure to detect them,
• unnecessary warnings, e.g. when the restriction is no longer in force,
• errors due to outdated GPS data,
• delayed system response,
• over-reliance of the driver on technology, which can lead to reduced vigilance.

Some drivers feel impatient with the frequent messages and decide to deactivation of the system, especially when it does not operate with the necessary precision.

ZENBOX PRO - turn off the character recognition system when you want to

For drivers who prefer greater control over vehicle electronics, the ideal solution is ZENBOX PRO. It is a state-of-the-art device that allows Permanent deactivation of selected driver assistance systemsof which traffic sign recognition system.

ZENBOX PRO works non-invasively - no interference with the factory software or loss of warranty. Once installed, the driver gains the ability to:

• to switch off the TSR at any time,
• limit the number of messages and warnings,
• improve driving comfort in difficult conditions,
• to match the vehicle to your own driving style.

ZENBOX PRO is becoming increasingly popular among drivers who want full control of their car and appreciate functional but unobtrusive solutions. It's an effective way to manage functions that sometimes, instead of helping, can make driving difficult.

To sum up, sign recognition system is a useful technology that, however, does not always work perfectly. Thanks to the device ZENBOX PRO, you can decide for yourself when it is worth using it.

See also:

• Active vs. Passive Safety – What You Need to Know
• Start stop system - operation
• Mandatory passenger car equipment in 2025
• ISA System - How the Intelligent Speed Assistant Works
• ADAS system – what is it and how does it work
• Lane Assistant – How It Works
• Driver Fatigue Detection System – Does It Really Work?
• The most important safety systems in cars