If you are arrested for DUI, you will, in all likelihood, have to defend two separate cases. In addition to the criminal case, it is likely that the Department of Motor Vehicles will take action to attempt to immediately suspend your drivers license. If you have taken a blood or breath test which reveals an alcohol level greater than .08, you face a 90-day suspension of your drivers license (known as an admin per se suspension). If there is an allegation that you refused to submit to a blood or breath test, you face a one-year suspension of your drivers license (an implied consent suspension). For people who drive for a living, these consequence alone can be catastrophic.
In addition to a possible admin per se or implied consent suspension, if you are convicted of any DUI offense, there is a requirement you install an ignition interlock device on any vehicle that you operate. The ignition interlock requirement can be from six months to two years, depending upon the conviction. Until recently, people who drove company vehicles for a living could continue working as long as they informed their employer of this requirement, and the employer was willing to sign a form allowing the employee to operate a company vehicle without such device. Recently, that provision in the law was repealed. For many people, the ignition interlock device requirement is now enough to ruin a career.