Effectiveness and impact of alcohol interlock-controlled driving rights

Trafi Publications 06-2013

Anne Vehmas, Ramboll Finland Oy
Marita Löytty, Trafi

The study investigated the effectiveness and impact of alcohol interlock-controlled driving rights. The materials for the study consisted of a survey sent to all drivers who chose alcohol interlock-controlled driving rights, email surveys sent to police departments, district courts and alcohol interlock importers, as well as interviews of health care representatives and drivers. In addition, the driving rights, traffic violation data and causes of death of persons with alcohol interlock-controlled driving rights registered in the Traffic Information System, as well as the log data decoded from the alcohol interlocks of a single manufacturer were analysed in the study, and a review of other European countries' alcohol interlock practices regarding drivers guilty of driving while intoxicated was drawn up.

During the period 1 July 2008 – 12 June 2012, a total of 1,687 drivers held alcohol interlock-controlled driving rights, and 24 (1.4%) of these drivers died. Alcohol-related causes of death and suicides were much more prevalent among persons with alcohol interlock driving licences than in the general population. The average age of the drivers was 51, and 84% of the drivers were male. The youngest driver was 20 years old; the oldest, 82.

More than half of the drivers had been convicted of driving while intoxicated several times before receiving an alcohol interlock-controlled right to drive. Of all drivers, 54 (3.3%) were caught driving while intoxicated during their period of alcohol interlock-controlled driving rights. After the end of alcohol interlock-controlled driving rights, 41 (2.5%) drivers were caught driving while intoxicated. Thus, a total of 95 (5.7%) drivers were caught driving while intoxicated during and/or after their period of alcohol interlock-controlled driving rights. The recidivism percentage of alcohol interlock users seems to be significantly smaller than that of all persons convicted of driving while intoxicated (29–30%).

Most drivers said that alcohol interlock use had affected their alcohol use and helped them avoid driving while intoxicated. Based on the log data, alcohol interlocks used in controlled driving rights have prevented 12 000 instances of driving while intoxicated (≥ 0,5 ‰), and over 40 000 times a driver who had “had a few” (≥ 0,2 ‰) to start a vehicle for driving (the number includes also the cases with ≥ 0,5 ‰). Roughly a third of all drivers said they had kept or would keep the alcohol interlock in voluntary use after the end of the probationary period.

The average length of alcohol interlock-controlled driving rights was 506 days, i.e. slightly less than 18 months. Even though cases of interrupted driving rights were deleted from the material, 15% (229) of all alcohol interlock-controlled driving rights lasted less than the statutory 12 months. Many drivers complained of difficulties in obtaining information on the length of the probationary period before making the decision whether to acquire an alcohol interlock, and the duration of the period remained unclear for many even during use, since drivers had received contradictory information from different authorities. According to the district courts, likely explanations for the overly-short probationary periods included difficulties in interpreting the law, ignorance, negligence and human error.

Persons convicted of driving while intoxicated perceived the alcohol interlock in varying ways. At one end of the spectrum, the alcohol interlock was viewed as a problem, a nuisance in everyday life and a shameful reminder of driving while intoxicated. At the other extreme, the alcohol interlock was considered a helper, an aid in life management and safe travel companion, which prevented further mishaps. Most drivers felt exhaling into the interlock in public to be awkward. A tenth of all drivers concealed the existence of the alcohol interlock from everyone but their own family, and a few drivers even concealed it from their families.

Most drivers did not experience trouble with obtaining information, but according to 10–15% of those interviewed, no one was able to give advice on matters related to the alcohol interlock, and the information was scattered, unclear and too general. Drivers expressed a wish for more detailed information on the locations of vendors and installers of alcohol interlocks, the required appointment with a physician, duration of the probationary period, and the possibility to obtain an alcohol interlock driving licence even before the district court had made its decision. The general level of knowledge on the possibility of using an alcohol interlock has improved in recent years, but still more communication and instruction on alcohol interlock-controlled driving rights is required, for both drivers and authorities.

Many shortcomings were identified in the effectiveness of alcohol interlock-controlled driving rights. It is crucial to eliminate these shortcomings to make alcohol interlock use more common, with the positive effects on the safety of traffic this entails. The development recommendations formulated in the study are summarised below.

  • More communication on alcohol interlocks and alcohol interlock-controlled driving rights (An alcohol interlock campaign and website)
  • There should be drawn up clarifying instructions on alcohol interlock-controlled driving rights for district courts, police departments and health care professionals
    • Guidance from the Ministry of Social Affairs and Health regarding the content and objectives of discussion
    • Authorities could recommend the alcohol interlock to persons caught driving while intoxicated, as well as retaining the alcohol interlock in voluntary use after the probationary period.
    • Local cooperation meetings between the police, district courts and health care services
  • A log data register defined and maintained by the authorities should be created to store the decoded log data of all alcohol interlock manufacturers or their representatives in a uniform format.
    • Making use of alcohol interlock log data when, e.g. restoring driving rights and treating substance abuse, as well as for purposes of research and the compiling of statistics.
  • Authorities should define and approve all processes related to alcohol interlock use required from the devices' manufacturers or their representatives.
  • Proposed changes to the alcohol interlock-controlled driving rights process
    • Driving bans ordered for driving while intoxicated should be lengthened to equal the length of the probationary period of controlled driving rights.
    • A normal driving licence should be restored to the driver only once the alcohol interlock's log data is found to contain no rejected exhalations in the past six months. If a driver has attempted to set off under the influence of alcohol, the police could either extend the validity of the alcohol interlock driving licence until such time that all exhalations in the past six months have been accepted, or direct the person to substance-use monitoring and health-based alcohol interlock use.
    • A health care professional should evaluate each individual's need for discussion sessions, e.g. from one to three sessions.
    • A short driving ban before receiving alcohol interlock-controlled driving rights should be considered for all persons caught driving while intoxicated.
  • Device manufacturers and importers should improve the user instructions of alcohol interlocks and continue technical development to alleviate problems related to, e.g. exhalations and warming up.
    • Garages should be instructed on the handling of alcohol interlocks during servicing of the car.
    • The number of alcohol interlock log data-decoding stations should be increased, or a reliable method of remote decoding developed.
  • Subjects for further study include the various categories of persons with alcohol interlock driving licences (e.g. first-time-offenders, and recidivists) and instances of driving while intoxicated during a period of holding alcohol interlock-controlled driving rights.