Part 4: General deterrence and targeted enforcement

New Zealand Police: Enforcing drink-driving laws.

In this Part, we:

  • describe the Police's general deterrence and targeted enforcement strategies;
  • discuss how well frontline Police officers understand the general deterrence and targeted enforcement strategies; and
  • explain how the Police balance general deterrence and targeted enforcement when planning their daily or weekly activities.

Summary of our findings

The Police have clear national strategies to deter and detect drink drivers. The strategies use general deterrence and targeted enforcement to bring about the perception that drivers can be breath-tested "anywhere, anytime". The strategies, well understood throughout the Police, are based on, and supported by, international research.

Planning general deterrence and targeted enforcement activities is challenging. The Police must consider many factors and use their local knowledge, experience, and professional judgement to be flexible and plan effective activities to reduce drink-driving.

Districts manage the balance between general deterrence and targeted enforcement. This means that Police officers have considerable discretion to use updated intelligence and information about risks to assign their resources.

General deterrence and targeted enforcement distinguished

Strategies for general deterrence and targeted enforcement focus on preventing drink-driving by producing and maintaining the perception that such behaviour will be noticed and punished. In the 2011/12 Road Policing Programme, the Police explain their approach to enforcement:

To maximise perceptions of apprehension and therefore compliance, road-policing resources are deployed to be as visible as possible, to engage with large volumes of the driving population so as to increase awareness, and to be unpredictable in order to create uncertainty about where the Police are.

In carrying out their activities, the Police try to achieve a balance between going to places with high traffic volumes and a relatively low likelihood that drivers have been drinking (general deterrence) and places that might have lower traffic volumes but a much higher likelihood that drivers have been drinking (targeted enforcement).

General deterrence

To be effective, general deterrence activities need to be highly visible, involve strict enforcement, be repeated as often as possible, and be supported by a high-profile media campaign. In Parts 6 and 7, we assess how effectively the Police enforce drink-driving laws using these principles.

An example of the Police's general deterrence approach is booze bus operations, where many motorists are breath-tested at a roadside checkpoint.

Targeted enforcement

The purpose of targeted enforcement is to detect drink drivers by targeting high-risk times, places, and drivers.

The Police consider risks when planning targeted enforcement activities. They collect and analyse crash data, recorded offending, traffic complaints, and details of repeat offenders and repeat offending.

Examples of targeted enforcement include stopping vehicles when they leave pubs, sports events, and night clubs, and setting up a booze bus operation at a place and time where the risk of people drink-driving is high.

Police officers understand the enforcement strategy

In the Districts we visited, we noticed a lot of awareness and understanding of the strategies of general deterrence and targeted enforcement. Every Police officer we asked knew the "fatal five" priority areas that are closely in keeping with Safer Journeys and the Road Policing Programme.

One Police officer we spoke with, who had attended a two-week road policing course, was particularly knowledgeable about the principles of general deterrence.

Balancing general deterrence and targeted enforcement

Planning general deterrence and targeted drink-driving operations is challenging. The Police must consider multiple factors, including the best balance between general deterrence and targeted enforcement, performance targets, staff availability, the national advertising calendar, and other factors (such as local events, general crime suppression, public perceptions, agreements with local authorities, and any urgent matters that arise).

In practice, the Police do not always treat general deterrence and targeted enforcement operations as mutually exclusive. For example, we attended a booze bus operation on an Auckland motorway on-ramp at 4am on a Friday. The Sergeant told us that the time and place of the operation was chosen to catch drink drivers as they left night clubs. Between 4am and 6am, overall traffic volumes were low and the proportion of drivers who had been drinking was high. The Sergeant told us that the chance of catching drink-drivers decreased about 6.15am when traffic volumes increased because people were going to work. By then, the operation became less about targeted enforcement and more about general deterrence through high-visibility testing.

The Police use no set formula to balance general deterrence and targeted enforcement. They do not specify national risks and deployment patterns for road policing work. This is because:

  • the Police believe that patterns observed nationally are not necessarily present in all Districts; and
  • the success of intelligence-led policing depends on timely information and Districts being able to act on intelligence (see paragraph 4.10).

For those reasons, achieving the best balance between general deterrence and targeted enforcement operations is managed at the District level. To support Districts, the Police are exploring how to get a more intelligence-driven approach to road policing tactics by using geo-spatial mapping to overlay crash analysis data from the New Zealand Transport Agency and the Police's enforcement and ticketing work (see Part 7).

Meeting performance targets for breath tests

In 2011/12, the Police were funded to carry out two million compulsory breath tests from booze bus checkpoints and 700,000 mobile breath tests from patrol cars. The Ministers of Transport and Police decide on these figures, which are published each year in the Road Policing Programme.

International research supports combining checkpoint and mobile breath-testing as best practice to achieve the greatest reductions in crashes and be the most cost beneficial when carried out intensively and highly visibly. International research also shows breath-testing as the most effective way to deter drink-driving.

When carried out intensively, breath-testing can substantially reduce fatal and serious injury crashes at night. Australian research shows the effect of the testing lasts for at least two weeks after being carried out.

The Police use the number of checkpoint and mobile breath-tests carried out as performance targets. This can put pressure on Districts to prioritise operations to locations and times when traffic volumes are greatest but the risks of drink-driving are not necessarily high. The Police also need to run operations in rural areas, but those operations often affect few motorists and affect the Police's ability to meet performance targets.

Staffing enforcement operations

The Police use officers from Traffic Alcohol Group (TAG) units, Highway Patrol Units, Strategic Traffic Units, and General Duties Branches to carry out breath tests.

TAGs specialist units whose core role is to reduce drink-driving - are responsible for running booze bus operations and contribute most to the Police's high-visibility general deterrence strategies. The peer assessment of the Police carried out by German and Australian officers in 2009 (see also paragraph 3.17) found strong anecdotal evidence of the effectiveness of TAG units. Many countries have also had success using dedicated alcohol units.

Co-ordinating enforcement with national advertising

Each year, the New Zealand Transport Agency produces a calendar of national road safety advertising that outlines when drink-driving advertising campaigns will take place. This allows the Police to plan operational blitzes to coincide with the advertising campaigns. We have not specifically audited the Police against the general deterrence principle of publicity because the New Zealand Transport Agency is responsible for drink-driving publicity, advertising, and media campaigns. However, the Police officers we spoke with were well aware of the calendar, which was prominent on walls at Police stations and on the desks of road policing managers.

Local knowledge, experience, and professional judgement

The Police have no formula to balance the often competing priorities that influence planning and resourcing of drink-driving operations. Circumstances constantly change, meaning that the Police must rely on the information to hand and their considerable local knowledge, experience, and professional judgement to make decisions.

In the Districts we visited, experienced Police officers' local knowledge complemented the tactical assessments that Police analysts prepared. Local officers displayed a good understanding of their communities and where drink drivers might be. This included the back roads and arterial routes that drink drivers might use and places where the Police might expect problems. The tactical assessments and planning process gave senior officers discretion and flexibility in how and where they carried out their drink-driving operations. We saw senior officers deciding how long to leave booze bus checkpoints open (before impeding peak traffic flows), what streets to patrol in cars, and how long to monitor a targeted hotel.

Police operations can target more than just drink-driving. A strength of the Police's drink-driving operations is that they provide flexibility to work on the 13 priorities in Safer Journeys and, in particular, the "fatal five". The Police also use drink-driving checkpoints strategically to address other crime issues (for example, to increase their presence in response to burglaries in a certain area).

We saw Police officers deployed on drink-driving operations adjusting seatbelts, dealing with disqualified drivers, and ordering unsafe cars off the road. We attended one drink-driving checkpoint set up between 2.30pm and 4.30pm between two major high schools. The Senior Sergeant told us the highly visible operation had high-volume testing and targeted young drivers breaking the conditions of their learner and restricted licences - by driving without supervision and with passengers.

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