Alcohol interlock – what is it, how does it work and how much does it cost?

An alcohol interlock in a truck prevents the vehicle from starting if the driver has a breath alcohol concentration above a set threshold. Before starting to drive, the driver performs a test using a mouthpiece, and the device analyzes the sample and transmits the information to the vehicle control system.

The alcohol interlock in a truck is used both in single vehicles and truck fleets. This is important because police data from 2025 clearly shows that the problem of people drinking behind the wheel is growing. In the Łódź Voivodeship alone, it was revealed 4,676 drunk drivers, which means an increase of 4.4% compared to 2024. Alcohol poses a huge risk on the road, despite controls and stricter regulations.

We explain how an alcohol interlock works and when it will work. 

Alcohol interlock – what is it?

According to the definition of the West Pomeranian Police: Alcohol lock is a technical device that prevents the engine of a motor vehicle or rail vehicle from starting if the alcohol content in the exhaled air is at least 0.1 mg of alcohol in 1 dm³.

What is an alcohol interlock in a truck?

An alcohol interlock prevents the driver from starting the vehicle if they are under the influence of alcohol. The device works like a breathalyzer connected directly to the ignition system. If the driver blows air before starting the engine and it contains an unacceptable level of alcohol, the car will not start.

Alcohol interlocks have been in place in Polish law since 2015. Importantly, they can be installed both voluntarily and by court order as an alternative to a driving ban.

Is an alcohol interlock mandatory in a truck?

In Poland, the installation of an alcohol interlock in a truck is not currently mandatory for all vehicles. However, a business owner may choose to install it as an additional safeguard for their fleet against drivers under the influence of alcohol. The interlock can also be used in certain cases as an alternative to a driving ban, based on a court decision.

How does an alcohol interlock work technically?

The alcohol interlock consists of a breath alcohol testing module and a control unit connected to the vehicle system. Before starting the engine, the driver performs a test by blowing into the device's mouthpiece.

If the result is below the set threshold, the system allows the vehicle to be started. If the device detects that the permissible value has been exceeded, blocks the possibility of starting the engine. The operating mechanism itself is simple, but correct installation requires appropriate integration with the specific vehicle's electronics.

In solutions intended for fleets, additional functions are also important, such as: event recording, protection against attempts to bypass the device or the possibility of repeating the test in certain situations – the scope of these functions depends on the specific model.

Regular exercise is also important calibration and control of the device. Polish technical requirements stipulate calibration every 12 months.

Thanks to this, the alcohol interlock is not an ordinary breathalyzer used before driving, but a component integrated into the vehicle that can physically prevent it from starting when alcohol is detected.

Alcohol interlock for the truck fleet

Entrepreneurs decide to install locks in trucks when want to reduce the risk of road accidents, protect cargo, take care of the company's reputation, and at the same time meet internal safety standards. 

Alcohol limits and consequences for drivers

Is it safe to drive after drinking just one beer? Contrary to appearances, it's not as obvious as it sounds... Just half a liter of beer can raise your blood pressure. blood alcohol concentration up to approximately 0.2 per mille, and in exhaled air to over 0.4 mg/l, which in Poland means exceeding the permissible limit. 

National regulations vary. In Poland, the blood alcohol content limit is 0.2‰, and professional and novice drivers often require complete sobriety. In many European countries, the thresholds are slightly higher, ranging from 0.5–0.8 per mille. 

Below are the blood alcohol limits in selected European countries.

Alcohol interlock in a truck and transport to Germany

Companies implementing truck transport to Germany They should also be aware of local regulations regarding driving under the influence of alcohol. In Germany, there is currently no general requirement to equip all trucks with alcohol interlocks. At the same time, the topic of such devices is being developed at the European level – new vehicles are being technically prepared for easier installation of alcohol interlock systems.

This doesn't mean, however, that truck drivers are free to drive after drinking alcohol. German law provides for liability for driving under the influence of alcohol, and with a blood alcohol concentration 0.5‰ of alcohol in the blood or 0.25 mg/l in exhaled air driving a vehicle is an administrative offense.

Therefore, in the case of fleets carrying out international transport, the alcohol interlock can be treated as additional protection against driving by a drunk driver, regardless of the obligations arising from the regulations of the country where the vehicle is located.

How much does an alcohol interlock cost?

The cost of an alcohol interlock depends primarily on device model, vehicle type and scope of installation and integration with its electrical system. Therefore, the total cost should be considered more broadly than just the price of the breathalyzer itself.

When choosing a solution, it is worth considering:

• purchase of the device,
• assembly and integration with the vehicle system,
• first and later calibrations,
• periodic service,
• possible integration with systems used in the fleet.

In the case of devices intended for fleet use, not only the purchase price is important, but also approval, technical requirements, installation method and subsequent operating costs. Before choosing a specific solution, it's worth checking whether the device is suitable for your vehicle type and meets the required standards.

In Poland, the regulations regarding the technical requirements of alcohol interlocks refer, among others, to the standard PN-EN 50436-1, and the device is scheduled for calibration every 12 months.

Want to know the cost of an alcohol interlock for a specific vehicle or fleet? Contact ATROM – we'll tailor a solution to your fleet's specific needs and provide a personalized quote.

Alcohol interlock for vehicles offered by ATROM, i.e. safety for fleets and drivers

Are companies increasingly implementing alcohol interlocks? Absolutely. And not because they have to, but because they want to reduce the risk of accidents, fines, and legal consequences. In response to these needs ATROM offers modern alcohol interlock systems designed for fleet vehicles, trucks and heavy machinery and equipment.

We deliver certified car breathalyzer Integrated directly into the vehicle's ignition, the device reliably indicates alcohol concentration. If the driver is under the influence of alcohol, the vehicle will not start. This alcohol interlock device works well in both individual vehicles and fleets of dozens or even hundreds of vehicles.

The system can be used not only in passenger cars and trucks, but also in:

• specialized vehicles,
• construction machines,
• agricultural equipment,
• devices used in industry.

Devices from our range they have a durable polycarbonate housing, resistant to mechanical damage and difficult operating conditions. The easy-to-read LCD display ensures intuitive operation. The hypoallergenic mouthpieces are a major advantage, ensuring driver safety and health, even during frequent shifts behind the wheel. 

Is an alcohol interlock in your car a wise choice? 

Without a doubt. The employer limits the risk:

• road accidents,
• financial losses,
• downtime,
• legal liability,
• loss of company reputation.

FAQ – Alcohol Interlock and Driver Safety

1. What is an alcohol interlock?
An alcohol interlock is a device installed in a vehicle that prevents it from starting if the driver is intoxicated. This effectively prevents drunk driving.

2. How does an alcohol interlock work in practice?
Before starting the vehicle, the driver must blow into the mouthpiece, and the device analyzes a 1-dm³ sample of air. If the result exceeds the allowable limit, the system will not allow driving.

3. Who can benefit from installing an alcohol interlock?
Individuals convicted of driving under the influence of alcohol may apply for the installation of an alcohol interlock device as an alternative to a lifetime driving ban. Additionally, an interlock device can be voluntarily installed in company vehicles.

4. Does an alcohol interlock affect your driving license?
Yes, the installed device allows you to maintain your driving privileges during the period of the ban. Drivers who follow the interlock's operating procedures do not risk having their license suspended.

5. How long does it take to install an alcohol interlock in a car?
Installing an alcohol interlock device is usually quick and performed by a specialized service center. The device installed in the vehicle requires calibration every 12 months.

6. Does the alcohol interlock work in trucks?
Yes, modern systems can be installed in trucks and specialized vehicles. A vehicle interlock device ensures that driving vehicles not equipped with an interlock device is impossible if the driver is intoxicated.

7. What are the consequences of driving under the influence of alcohol?
Exceeding the blood alcohol content (BAC) limit is treated as either a misdemeanor or a felony, depending on the alcohol concentration and the offender's characteristics and personal circumstances. In extreme cases, the court may impose a lifetime driving ban.

8. Can anyone install an alcohol interlock in their fleet?
Yes, businesses can equip their vehicles with an alcohol interlock to reduce the risk of accidents and protect their third-party liability insurance. The system checks whether the driver's driving poses a risk to the safety of other road users.

9. How often should I calibrate my alcohol interlock?
Every installed device requires regular calibration at an authorized service center, typically once every 12 months. A document confirming the calibration of the alcohol interlock is required to maintain the full validity of the interlock installation.

10. When is it worth implementing an alcohol interlock in your company?
An alcohol interlock device reduces the risk of accidents, financial losses, and damage to a company's reputation. It's especially worthwhile to implement it in trucks and fleets where driving poses a risk to convicted felons or other road users.