In the State of New Hampshire, a driver is not eligible to use an ignition interlock device (IID) until after the license suspension period has been served. If a driver has been convicted of driving while intoxicated (DWI), the courts may order the installation of an IID under three (3) circumstances: the driver was convicted of an Aggravated DWI, the driver has been convicted of several DWIs in or outside of the State, or the driver was convicted of driving with a suspended or revoked license resulting from a DWI. Courts may also issue the installation of an IID to drivers under age twenty-one (21) who had their license revoked or suspended due to a DWI.
Unless the offender is under age twenty-one (21), the IID must be installed for at least one (1) year and not more than two (2) years. If the offender was under age, the IID may be installed for one (1) year or until the individual turns twenty-one (21), whichever is longer. When a court orders an IID installation, the device must be installed on all vehicles registered to and operated by the offender. The device must be monitored and calibrated at least every ninety (90) days and rolling re-tests are standard. The offender is responsible for all costs associated with the use of an IID.
In the State of New Hampshire, IIDs record the following information:
- Number of engine starts and attempts to start
- Rolling re-test reports
- Attempts to circumvent or tamper with the device
- Number of times the breath test was avoided
- The breath alcohol content results for each test