Kärki, O.V.
The Finnish Road Administration/Vaasa Region, P.O.Box 93, 65101 Vaasa, Finland
(Until May 2002: VTT Building and Transport, P.O.Box 1800, Espoo, Finland)

Abstract

The objective of the study was to assess the possibilities of using an ignition interlock in tackling drink-driving and of further implementing a field trial on interlocks in Finland.

The following aspects were considered in the study: target groups, legal and technical requirements, acceptance, costs and accident reduction potential. It was suggested that a field trial on the interlocks for DUI (driving under the influence of alcohol) offenders be conducted. The target group for the prospective field trial would comprise DUI offenders who have had a provisional driving licence suspension. The field trial would be voluntary-based and user-paid.

A law should be introduced to enable the use of a vehicle equipped with an interlock inside the borders of Finland for a 3-year, fixed-term probationary period. The interlock usage-time would correspond with the original driving suspension. It was estimated that fewer than 10 % of firsttime aggravated DUI offenders or recidivists would volunteer for the trial. Recidivists would benefit most from the interlock use. It was estimated that a 3-year field trial, with 50 DUI recidivists participating at a time, would prevent at least one personal injury and over 170 000 driving-kilometres over 0.5 BAC (blood alcohol concentration).

Introduction

Alcohol is one of the major contributory factors to road traffic accidents, and in particular, to accidents with severe consequences. Even though the number of drunken drivers, with a BAC over the Finnish legal limit of 0.5 g/l, in the traffic flow has shown a slight decreasing trend (currently less than 0.2 %), the percentage of alcohol-related accidents (with a BAC of over 0.5 g/l) of all fatal motor vehicle accidents in Finland has remained at over the 25 % level (Mäkinen & Veijalainen 1997). However, the number of drunken drivers in the traffic flow in the lowerclass roads is considerably higher. In Finland the proportion of aggravated DUI offenders (BAC over 1.2 g/l) in the traffic flow is usually at least 50 %, and this group is involved in over 80 % of fatal DUI accidents. An average driving licence suspension period after first DUI offence is five months. Aggravated DUI offenders and recidivists usually get eight months' licence suspension periods. A driving licence is not given to persons dependent on alcohol. Almost 50 % of DUI offenders have previous DUI offences in Finland; on top of that, this share near the capital Helsinki is over 50 %.

Traffic regulations permitting random roadside breath tests and a support of DUI enforcement campaigns have deterred an increase in drunken driving in Finland. This will not necessarily be the case in the future, owing to steadily increasing alcohol consumption and the deregulation of strict Finnish alcohol-pricing policy that will come into effect in 2003 and 2004 with European Union regulations. The long-term traffic safety objectives require some 30 % reduction of road traffic fatalities in Finland in the next ten years. This aim requires also a reduction of alcoholrelated fatalities in traffic. One of the means recommended by the advisory board of traffic safety matters in Finland in the late 1990s was implementing an ignition interlock programme in Finland.

The Technical Research Centre of Finland (VTT) studied possibilities of implementing a pilot alcohol interlock programme in Finland. The project was supervised and financed by a group comprising members from the Ministry of Transport and Communications, the Ministry of Justice, the Central Motor-Vehicle Register and the Finnish Motor Insurers' Centre. Simultaneously with this study, VTT participated in a feasibility study on the interlocks in the EU context. This paper concentrates on the Finnish feasibility study.

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Methods

The Finnish feasibility study on the interlocks was designed to help determine whether a field trial on the interlocks and further interlock programmes are feasible in Finland. At first, a literature study of the development and the current state of the art of the interlocks and the interlock programmes was carried out. Several interlock studies (Baker et al. 1997, Marques et al. 2000, Beirness 2001, etc.) were reviewed. In addition to the project's supervisory group, experts from the police and National Public Health Institute were consulted. The project benefited also from the Swedish ignition interlock programme.

A questionnaire survey of drunken driving offenders was conducted in co-operation with five police districts of Finland. The objective of the questionnaire was to determine the acceptance of voluntary interlock use as an alternative to a driving ban among DUI recidivists. Furthermore, the willingness to pay for the interlock use was investigated to determine whether interlock use combined with rehabilitation would be feasible in Finland. Recommendations for the prospective field trial on the interlocks were given by VTT with the assistance of the project's supervisory group.

The technical solutions and standards of the interlocks were compared by means of a literature study and expert interviews. European Union legislation was utilised in technical matters as well as in alcohol-dependence matters.

The effects of the interlock use on traffic safety were estimated on the basis of expected changes in the proportion of vehicle-kilometres driven under the influence of alcohol. Rough estimates of cost-effectiveness of interlock use were also made.

Results

The questionnaire

Some 200 answers were expected to the questionnaire survey, but only 99 DUI offenders answered. The questionnaire was mostly aimed at recidivists (29 answers) and first-time aggravated DUI offenders (45 answers). The main results showed that every fifth respondent would pay at least €168 a month for one year for being allowed to drive with a vehicle equipped with an interlock instead of driving licence revocation. €168 a month was estimated to be the monthly fee for participating in an interlock programme with rehabilitation. Some 40 % of the respondents would pay at least €70 a month, which was estimated to be the minimum monthly fee for interlock use without rehabilitation. Over half of the offenders would not take an interlock.

Furthermore, the results showed that those DUI offenders whose households have monthly gross income over €2520 would be more willing to pay for interlock use than those with a lower income ( 2: df = 1, p < 0.05), (Figure 1). However, some offenders whose monthly gross income is less than €840 expressed their willingness to pay for the interlock use. Owing to low income, their ability to pay for the interlock use is questionable.

Figure 1: Willingness to pay (€/month for one year) for interlock use according to monthly income of the households of DUI offenders

There were indications that recidivists would be more willing to pay for interlock use than firsttime aggravated DUI offenders. However, this finding is not significant because of the small sample. On the basis of the results from the questionnaire and several user-paid interlock programmes, it was estimated that under 10 % of DUI offenders in Finland would pay some €80 a month for interlock use for the period their licence would be suspended because of a DUI offence, on average 5 to 8 months.

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Effects of the interlock on traffic safety

Many studies have indicated that the interlocks effectively prevent drunken driving during the period of interlock installation. Once the interlock is removed from the vehicle, the recidivism rates tend to increase again to the level prior to interlock use. Despite several studies of the effects of the interlock on recidivism, there are not many studies about the effects of the interlock on crash-rates or severe accidents. At least preliminary results from the interlock programme in Quebec, Canada (Dussault & Gendreau 2000) indicated that both casualty crashes and property damage only crashes decreased significantly, both during the interlock installation period and during a short period after interlock removal.

Within the frames of the Finnish feasibility study, some evaluations were made of the effects of the interlock on DUI mileage, personal injuries, and fatalities in Finland. The main calculations, which include interlock use by DUI recidivists only, are presented in Table 1.

Cost-effectiveness of interlock use

2x50 interlocks for 6 months (50 interlocks at a time for a year):
Costs savings because of accident reductions:
0.044x1.93x10⁶ € (cost of a fatality) + 0.57x0.25x10⁶ € (cost of a personal injury) = 227 000 €
Costs of the 6 months interlock use to users:
2x50x750 € = 75 000 €
Cost effectiveness (other costs than cost to interlock users are not taken into account):
227 000 €/75 000 € = 3.0

Recommendations for a field trial on the interlocks in Finland

VTT and the project's supervisory group recommended that a field trial on the interlocks for DUI offenders be conducted. A law should be introduced to enable the use of a vehicle equipped with an interlock inside the borders of Finland for a three-year, fixed-term probationary period. The interlock usage-time would correspond with the original driving suspension. DUI offenders who have had a provisional driving licence suspension enforced by the police would be able to participate. Drug users and those dependent on alcohol would be excluded. No hard suspension would be required. The field trial would be voluntary-based and user-paid. It was recommended that the prospective field trial be administrated by the Central Motor-Vehicle Register.

The objectives would be to determine the practical problems of interlock use and the development needs. In addition, the acceptability, cost-effectiveness and public opinion on using interlocks would be measured. Furthermore, requiring interlock use by recidivists as a condition of driving licence reinstatement would be considered, as well as the need for establishing a longterm interlock programme. At the moment the Ministry of Transport and Communications is preparing legislation for the field trial according to the results of the feasibility study. A final decision on implementing the field trial on the interlocks has not been made and more a detailed design is required before implementing the field trial. A decision from the Finnish parliament on the field trial is also required.

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Table 1: Evaluations of the effects of the interlock on DUI mileage, personal injuries and fatalities in Finland. Interlock use by DUI recidivists only is included in the calculations

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Discussion

On the basis of the results of the questionnaire and many voluntary interlock programmes, the acceptability of the interlock is high enough to enable a small-scale field trial on the interlocks in Finland. Despite relatively short driving suspensions for DUI offences in Finland, implementing a field trial on the interlocks was recommended. It should be noted that changing the average lengths of driving suspensions because of the field trial on the interlocks is not possible. Other countermeasures, like rehabilitation only, are considered before making a decision on a field trial on the interlocks.

In March 2002, it seems that a field trial on the interlocks will be implemented in Finland, provided that parliament accepts it. Encouraging results from foreign studies have been one factor to encourage the Ministry of Transport and Communications preparing legislation for the field trial.

It may be difficult to make final conclusions of the suitability of the interlock to Finland according to the prospective field trial. However, many practical problems will probably be solved by implementing the interlock gradually, step by step. There is a clear need to fight drunk-driving also by technical means in Finland.

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References

1. Kärki, O. 2001. Alkolukko rattijuopumuksen ehkäisyssä. Esiselvitys. [Breath alcohol ignition interlock device. Feasibility study]. Technical Research Centre of Finland. Espoo 2001. Research Notes 2118. 85 p. + app.

2. Mäkinen, T. & Veijalainen, T. 1997. Drunk-driving reduced by half in Finland. International Conference: Traffic Safety on Two Continents. Lisbon, PT, 22 - 24 Sept. 1997. Traffic Safety. Lisbon (1997) No: 23/9, 10 p

3. Baker, E., Rauch, W. & Beck, K. 1997. Ignition Interlock Program Lowers Re-arrest Rate in Repeat Offencers. News release 23th April 1997. University of Maryland at College Park.

4. Marques, P. R., Tippets, A. S., Voas, R. B. & Beirness, D. J. 2000. Predictors of failed interlock BAC tests and using failed BAC tests to predict post-interlock repeat DUI's. The 15th International Conference on Alcohol, Drugs and Traffic Safety, Stockholm, Sweden, 22 26 May, 2000.

5. Beirness, D. J. 2001. Best Practices for Alcohol Interlock Programs. Traffic Injury Research Foundation. Ottawa, Canada.

6. Dussault & Gendreau. 2000. Alcohol ignition interlock: One-year’s experience in Québec. The 15th International Conference on Alcohol, Drugs, and Traffic Safety, Stockholm, Sweden, 22-26 May, 2000.

7. Driving licence register of Finland.

8. The Finnish Motor Insurers’ Centre (VALT). 2001. Yhteenveto liikennevahinkojen tutkijalautakuntien tutkimista rattijuopumusonnettomuuksista vuosina 1968-2000. 29 p. + 1 app. ISBN 951-9346-05-8.

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