Program Profile: Engine Immobilizers (Australia)

This program uses devices that prevent a vehicle from starting without receiving the correct signal from the driver, with the goal of reducing car theft. This signal may be communicated through a transponder, electronic key, or other mechanism. The program is rated Effective. The program demonstrated a statistically significant reduction in theft of cars with engine immobilizers, compared with theft of cars without engine immobilizers.

An Effective rating implies that implementing the program is likely to result in the intended outcome(s).

Program Goals

Engine immobilizers are devices that prevent a vehicle from starting unless they receive the correct signal from the driver. The goal of these systems is to reduce car theft.

Program Components

Engine immobilizer devices isolate the ignition system, the fuel system, the starter engine, or a combination of these systems. In order for a vehicle to start, the device must first receive a signal, which can be communicated in a number of ways:

• Transponder (usually built into original keys)
• Remote key (a handheld device that sends a radio or infrared signal)
• Electronic key
• Coded keypad
• Key switch

Immobilizers penetrate car markets in different ways. For instance, in Australia, since 2001, it has been compulsory for all new vehicles to have an immobilizer device installed that meets the Australian Design Requirements (AS/NZS 4601:1999) that were issued in 1999. The Western Australian government also started subsidizing the aftermarket installation of such devices in 1997 and made such installations required in 1999.

Study 1

Potter and Thomas (2001) used a time series design with multiple experimental and comparison groups to compare the effectiveness of six main kinds of engine immobilizers used in Australia. The researchers used theft and registration data from across Australia. The analysis compared theft rates for each group of vehicles fitted with a particular kind of immobilizer with theft rates for remaining vehicles over time. The analysis only assumed the presence of an immobilizer device if it was standard for a vehicle model and thus did not account for any aftermarket installations. It included some specific case studies of particular models, before and after these were fitted at manufacture with an immobilizer. The analysis undertook some interstate comparisons of immobilizer effectiveness and also included a detailed study of the voluntary and compulsory fitting of immobilizers to vehicles in one state, Western Australia.

The total number of stolen vehicles for the study exceeded 100,000. Of the vehicles stolen, 106,620 did not have an immobilizer and 10,286 did have an immobilizer. Certain areas had data for up to 11 years. Generally, data was collected for 1990 through 2000.

The study did not address the cases where the trend of reduced theft preceded the installation, nor whether the people in question moved from secure to nonsecure cars.

These sources were used in the development of the program profile: