Dutch program using in-car alcohol lock cuts drunk driving long after end

A Dutch program that required drivers to install in-car breathalyzer devices, known as alcohol ignition interlocks, significantly reduced repeat drunk driving—even after the program ended—according to new research from Vrije Universiteit Amsterdam. The study covers the introduction of the Alcoholslotprogramma in 2011 and its termination in 2016, showing lasting behavioral changes among participants despite the program’s cancellation on legal grounds.

An alcohol ignition interlock is a device installed in a car that requires the driver to pass a breath test before the vehicle can start. If the driver’s blood alcohol level exceeds the legal limit, the car will not start.

Motorists who were required to use an alcohol ignition interlock were less likely to drive under the influence after the program ended than comparable drivers who never had such a device, the university said. Researcher Martine Blom said the system helped participants change entrenched behavior. “The alcohol ignition interlock helps drivers change their habits, which significantly improves road safety,” she said.

The Dutch Alcoholslotprogramma, known as ASP, was introduced in 2011. Under the measure, vehicles belonging to people convicted of driving under the influence were fitted with an alcohol ignition interlock. In some cases, motorists stopped by police for suspected drunk driving could also be required to install the device.

Drivers enrolled in the program were also required to follow an educational course that included personalized feedback aimed at reducing repeat offenses.