Penal Code §49.09(g); §521.241 et seq.; Code of Criminal Procedure; 42.12
For a first or subsequent offense: The court must order offender to install ignition interlock devices on all of the motor vehicles he owns for the period of license suspension. The offender can choose a hard suspension with no interlock.
When applying for an occupational license, the court may require a first offender and must require subsequent offenders within 10 years to only operate vehicles that are equipped with ignition interlock devices.
Unless the interests of justice indicate otherwise, a magistrate shall require an offender (Intoxicated Assault, Intoxicated Manslaughter or a subsequent DWI offense), after release from confinement, to only operate vehicles that are equipped with ignition interlock devices.
Exemption: Employer.
Source: National Conference of State Legislatures
| How soon can ignition interlock be installed? | Duration of ignition interlock | |
| First offense .08 to .14 BAC | Upon revocation | 90 days to 1 year |
| First offense .15 BAC or more | Upon revocation | 1 year |
| Second offense | Upon revocation | 1 year |
| First refusal | Interlocks not available for first-time refusals | Interlocks not available for first-time refusals |
| How many times an interlock stopped a drunk driving start (.08% or more) in Texas?
244,991 From December 1,2006 to December 1, 2016 |
Source: MADD
