This study provides convincing evidence that vehicle immobilizers are effective mechanisms for reducing the risk of a vehicle being stolen within the Australian vehicle fleet.
An engine immobilizer is an electronic device that acts to control the functioning of a vehicle's ignition system, fuel system, the starter engine, or a combination of these three systems. The immobilizer will not allow the vehicle to be started without first receiving the correct signal from the person attempting to start the vehicle. This signal can be communicated to the immobilizer unit in a number of ways. These include the use of a transponder (electronic proximity device that convents electronically coded signals into radio signals); a remote key; electronic key; coded keypad; or a key switch. The transponder system is favored by manufacturers of the newer immobilizers and is generally perceived to be the most impervious to theft. Data from the current study support the theory that vehicles with immobilizers are much less likely to be stolen than their non-immobilized counterparts; however, the notion that immobilizers reduce opportunistic theft but have less impact on professional theft is confirmed by the fact that rates of theft for immobilized vehicles are lower in States that do not have a large level of professional theft. Additional strategies are required in order to counter professional theft of motor vehicles. Most of the systems that meet the Australian Standard (i.e. encrypted, encrypted-radio remote, and read only) are the best deterrents to theft, with rates of theft for these vehicles being significantly lower than vehicles with other types of immobilizers. Apparently, the systems that have a timed override, radio remote, or ignition dependent provide less protection. Still, these systems out-perform those with no immobilizer system. 26 tables and 14 figures