Renault is testing a new way of stopping drunk drivers before they even move: putting a finger on a sensor could be enough to determine whether someone has had too much to drink. The idea sounds futuristic, but it is not entirely new. Car makers and researchers have been experimenting with alternatives to the traditional breathalyzer for almost two decades.
What makes Renault’s latest project interesting is the way it wants to integrate the technology invisibly into an ordinary car, combine it with driver-monitoring cameras, and potentially bring it to production before the end of the decade.
Futurama innovation program
The system is being developed within Renault Group’s Futurama innovation program and was first shown on the R-Space Lab concept earlier this year. Renault described it then simply as a tactile alcohol detector, intended among other things to help young drivers avoid driving after drinking.
During a recent visit by French magazine L’Argus to Renault’s Futurama facility at Guyancourt, engineers disclosed more details. The driver would place a finger on a sensor before starting. The system would estimate alcohol concentration and compare the result with a predefined threshold. If that threshold were exceeded, the car could refuse to start.
Renault is also studying remote configuration. Parents could theoretically set a zero-alcohol limit when lending a car to a young driver, while fleet operators could impose their own thresholds.
That immediately creates an obvious loophole: let a sober passenger provide the finger. Renault therefore wants to link the sensor to the car’s interior cameras so the vehicle can verify that the person being tested is actually the driver.
Clinical trials are planned to determine whether the measurements are sufficiently reliable. Some technologies developed through the R-Space Lab program could be integrated into Renault’s next-generation RGEV Medium 2.0 platform from around 2028 or 2029.
Renault is not the first
The underlying idea is much older. In 2007, Nissan demonstrated a concept car with an alcohol sensor integrated into the transmission selector. It analyzed perspiration from the driver’s palm and could lock the transmission if alcohol was detected. Nissan also experimented with cabin alcohol sensors and cameras monitoring the driver’s eyes and behavior.
In the US, an even more ambitious program has been running since 2008. The Driver Alcohol Detection System for Safety, or DADSS, is backed by the US road-safety authorities and major car manufacturers.
One of its technologies uses near-infrared light to analyze alcohol concentration through the skin. A sensor could theoretically be incorporated into a start button, a gear selector, or a steering wheel, allowing the driver to be tested by simply touching a part of the car.
Development of that touch system continued until 2025, when funding constraints forced the program to concentrate on another technology: passive breath detection.
That approach could eventually be even less intrusive. Sensors positioned near the driver analyze normal exhaled air without requiring anyone to blow into a tube. DADSS expects its latest reference design to be completed this year, with licensing to automotive suppliers potentially beginning in 2027.
Renault has not disclosed exactly how its finger sensor works, so it cannot yet be assumed that it uses the same infrared spectroscopy.
Harder than it sounds
The difficulty is not detecting alcohol. It is doing so accurately enough to immobilize somebody’s car. US safety regulator NHTSA concluded earlier this year that no current production system can yet passively measure alcohol levels at or above the legal limit with sufficient accuracy for widespread use.
Even tiny error rates become problematic when applied to billions of journeys. A false positive could leave a completely sober driver stranded, while a false negative could allow someone who is impaired to drive.
Touch sensors also have to deal with cold fingers, sweat, skin differences, hand cream, dirt, and years of automotive heat, frost, and vibration. That helps explain why promising concepts demonstrated by Nissan, Toyota, and others never became everyday equipment.
Volvo came closer with its Alcoguard, launched in 2008 as a factory-integrated option. It still required the driver to blow into a wireless handheld breathalyzer; by 2010, it cost around €850, plus €50 to €90 for installation.
Regulation is moving closer
Renault’s timing is nevertheless interesting. Since July 2024, newly registered vehicles in the European Union must include an interface that facilitates the installation of an alcohol interlock. The interlock itself is not mandatory, but the technical groundwork is already required.
Euro NCAP’s latest safety protocols also give increasing importance to technologies capable of recognizing driver impairment, including alcohol and drugs.
That means alcohol detection could gradually evolve from equipment associated mainly with convicted drink-drivers into another integrated vehicle-safety function, alongside fatigue monitoring, automatic emergency braking, and speed assistance.
The exceptional part would be if Renault finally succeeds where those earlier projects struggled: turning the idea into something cheap, reliable, and unobtrusive enough to fit millions of ordinary cars.
