Highway Code

Mandatory alcolock: where it is fitted, how it works and how much it costs

Alcohol interlock becomes mandatory for convicted drink-drivers. The device prevents the engine from starting if alcohol is detected in the exhaled air. The article provides information on the operation, costs and concerns raised about the installation and maintenance of alcolocks.

by Rome Editorial Staff

24 March 2025Aggiornato il 3 luglio 2025 alle ore 08:31

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Hard times for those who like to drink alcohol before driving and have already been found behind the wheel with a blood alcohol level above the permitted limits. Transport Minister Matteo Salvini has in fact signed the decree initiating the use of alcolocks, the devices that repeat offenders will have to use in cars. If the alcohol level is too high, the car will not start. Some professionals in the sector, appraisers and coachbuilders in particular, had already expressed doubts about this measure contained in the new Highway Code. Starting with the price, which - they said - was around EUR 2,000 per car. But it is now decided.

Salvini signs the decree

Minister Matteo Salvini,' the MIT announced, 'has signed the decree defining the characteristics and methods of installation of the alcolock device. This text provides precise guidelines to authorised workshops for fitting and to users. It is one of the most significant innovations introduced by the new Highway Code, in force since 14 December. The alcolock is a system that prevents the vehicle from starting if the driver fails a breath test. The engine will only start if the alcohol level is zero. The new code,' explains the MIT, 'makes the installation of alcolocks compulsory for drivers already sanctioned for driving with a blood-alcohol level above 0.8 g/l, making it a key measure for repeat offenders, who will only be able to drive vehicles on which such a device is installed'.

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Obligations for producers

The decree stipulates that alcolocks can be installed on different categories of vehicles for the transport of both persons and goods and will have to meet the standards of European legislation. There are specific obligations for manufacturers, who will have to provide detailed instructions for installation, use and maintenance. Authorised installers will play a crucial role, having to apply a special seal to prevent any attempt at tampering. In case of roadside checks, the driver will have to show the original installation declaration and the valid calibration certificate of the device. The installation of the alcolock will not require an update of the single vehicle registration document.

Authorised Installers

The MIT will publish on the website www.ilportaledellautomobilista.it the list of authorised installers and vehicle models compatible with each type of alcolock. Among the doubts already expressed at the launch of the code, Aiped, the Italian Association of Damage Experts, claimed, among other things, that the Ministry of Transport's decree on alcolocks 'contains some criticalities that could give rise to legal disputes and appeals by motorists'.

For example, 'the installation and removal of the alcolock device are not among the technical operations subject to inspection and testing by the civil vehicle registration offices'. Federcarrozzieri is also critical: 'The Italian car fleet, in fact, is, as is well known, very old, with almost 22% of cars on the road being over 19 years old. There is therefore a real risk that on many particularly elderly cars it is technically impossible to install alcolocks'.

For whom it is mandatory

The device is an immobiliser and can only be brought into a non-blocking state after presentation and analysis of an accepted breath sample with an alcohol concentration of no more than 0 mg/l.

It is in fact an electronic device designed to prevent the engine from starting if the driver has a blood alcohol level above a certain threshold. It works like a digital breathalyser: before starting the car, the driver has to blow into a mouthpiece. If the system detects the presence of alcohol, it blocks the ignition and the car does not start.

It will be compulsory for anyone sentenced to a final sentence for driving under the influence of alcohol with a blood alcohol level above 0.8 grams per litre for two years after their driving licence has been suspended from six months to one year. If, on the other hand, the blood alcohol level exceeds 1.5 grams per litre, there will be three years of compulsory installation of the alcolock, following a suspension of one to two years ordered by the prefect.

L’installazione

In view of the adoption of the new device, the first doubts are already emerging. According to the MIT implementing decree, alcolocks will be fitted by authorised installers who will have to issue a calibration certificate and provide instructions for maintenance and use. Federcarrozzieri points out that the workshops will be chosen by the manufacturers themselves, to the detriment of free competition.

A self-destructive seal will prevent attempts to tamper with it, while all documentation will have to be kept in the vehicle and be shown in the event of a check, with the motorist being required to check that the calibration certificate for the alcolock is valid. Here, however, it is the Aiped experts who raise doubts. 'What happens,' they ask, 'if the seal is damaged by accident or as a result of a road accident? Who guarantees that a damaged seal does not automatically lead to an accusation of tampering?".

The cost

The cost of installation, to be borne by the motorist, is estimated at around 2,000 euros, to which must be added the cost of disposable mouthpieces and any maintenance or checks during the period the device will remain on the vehicle.

How it works

To start the engine, it will be necessary to exhale into the device, and only after a positive result - which is achieved with a concentration of zero mg/ml - can the engine be started. In the case of a single car in the household, each member will have to use the alcolock before driving. This will inevitably affect the other members of the household who are not sanctioned, even if the amount of alcohol permitted by the new highway code is 0.5 g/l.

Where it is already in use

The arrival of alcolock in Italy follows a choice that has long been applied in France, Austria, Belgium, Denmark, Poland, Lithuania, Sweden and Finland, where it is used for re-education instead of driving licence suspension, reducing recidivism as it helps to learn not to drink before getting behind the wheel.