The study, which was funded by the Department of Transportation, aimed at identifying cost-effective, antitheft performance criteria which could reduce the vehicle theft rate; at developing and testing an improved antitheft system that would comply with these criteria; and at recommending modifications to Federal Motor Vehicle Safety Standard 114, which specifies criteria for designers. The results of a vehicle theft survey and recommendations for antitheft performance criteria are given. A system design and the results of tests follow, as does a discussion of existing antitheft standards and recommended modifications of them. The system design includes a remote steering lock which is located in the steering gearbox and an electronic code transmission control which uses a keyboard code-insertion device. This system surpassed the recommended time-to-defeat criterion of 10 minutes. As a result of this study, two alternative safety standards are suggested. Both call for a theft protection system that activates automatically when the driver shuts off the engine and that is constructed so that no function critical to safe operation can be locked inadvertently while the vehicle is in motion. The first focuses on a minimum-defeat-time requirement and the second on limited accessibility characteristics. Photographs, diagrams, data tables, and appendixes containing 38 references, a list of information sources consulted, and a list of typical antitheft devices are included. Other appendixes present car thief interviews, information on lockpicking and pick-resistance locks, Motor Vehicle Safety Standard 114, and Economic Commission of Europe Regulation 18. For a related document, see NCJ 74475.