The Ignition Interlock System is one way Virginia is cracking down on DUI offenders. Any first time offender who has a blood alcohol level above .15 is required to have the device for 6 months. Second time offenders are required to have ignition interlock for at least 6 months, and up to three years. The system registers your alcohol level. If you blow below a .02, you've passed the test. You can then start your engine. Because the device requires a special breathing technique, it makes it difficult for someone else to blow into it for you. For more information, follow the link below.