Including driver assistance systems (ADAS) in vehicles has become the objective of the European Union as a key measure to avoid or reduce the number of accidents on the roads. On July 6, the new regulations will come into force that will force newly homologated cars to include several technologies, including the pre-installation for the anti-start breathalyzer, also known as alcohol interlock or alcolock (abbreviation for alcohol interlocks). Two years later, on July 6, 2024, this pre-installation will be mandatory in newly registered cars and light commercials, that is, new cars that leave a dealership.
The European regulation 2019/2144 on ADAS specifies that passenger cars and light commercial vehicles will have to include the pre-installation for an anti-start breathalyzer. Behind this decision is the high accident rate due to alcohol consumption, in Spain specifically it is the second cause behind distractions.
As I comment, what will be mandatory as of July 6 is pre-installation. European regulations leave each member state free to decide when they will be forced to use their own anti-start breathalyzer, for example, for recidivist drivers, for professionals or by judicial decision.
In the case of Spain, its use has been regulated in the new Law on Traffic, Circulation of Motor Vehicles and Road Safety: vehicles intended for the transport of people with more than nine seats (categories M2 and M3 or buses and coaches) with the pre-installation done, they will have to install and use the immobilizer breathalyzer.
What is the immobilizer breathalyzer?
The pre-installation consists of a standardized interface for all brands and models of new homologation so that the alcolock device itself can be easily installed.
Its function is to prevent the car from starting when it detects that the driver has consumed alcohol or has done so above the permitted limits. In Spain, the limits for the presence of alcohol in expired air are between 0.25 mg/l and up to 0.5 mg/l (between 0.15 mg/l and 0.3 mg/l for novices and professionals).
Undoubtedly, it is a very effective measure to reduce accidents caused by the presence of alcohol at the wheel. 
How does the alcolock work?
The driver of the vehicle will have to expire air in a breathalyser before starting the vehicle. The ethylometer will measure the concentration of alcohol in the breath and only if the degree of alcohol impregnation is within the programmed margins will the system allow the start. Otherwise, the engine cannot be started. How is it avoided? Thanks to an electronic vehicle immobilizer, one of the components of the anti-start breathalyzer together with the system for detecting the concentration of alcohol in expired air (alcolock).
The time in which the system detects the presence of alcohol after exhaling the air is just 25 seconds.
The pre-installation of the anti-start breathalyzer consists of the installation of a cable that is attached to the instrument panel to connect with the vehicle’s starting system.
What if I make a stop with the car?
In the event that the anti-start breathalyzer allows the engine to be started because it has not detected the presence of alcohol in the driver, what happens if the driver stops? Does the test have to be repeated before restarting the engine?
Here the key is in the duration of the stop, if it exceeds 30 minutes, the driver will have to repeat the test and breathe air into the breathalyzer again.
