Ignition interlock device requirements by state

An interlock order is usually described as one thing that happens after a DUI. It is not. Across the ten states on this page it is four different mechanisms — a court order, a department requirement, a license restriction and a program or permit you apply for — and which one you are under decides who can change it, when the clock starts and what ending it takes.

What an ignition interlock device is, and how it works

An ignition interlock device is a breath-alcohol tester wired into a vehicle’s ignition. Arizona’s definition is the fullest of those read here: a device “based on alcohol specific electrochemical fuel sensor technology that meets the national highway traffic safety administration specifications, that connects a breath analyzer to a motor vehicle’s ignition system”, constantly available to test whoever tries to start the vehicle, which deters starting unless the breath sample is below a preset level (A.R.S. § 28-1301(6), (10).) Washington’s is shorter and broader — equipment certified by the state patrol and “designed to prevent a motor vehicle from being operated by a person who has consumed an alcoholic beverage” (RCW 46.04.215.)

Two tests: at start-up, and while the vehicle is moving

The driver blows before the engine will start. Then, once the vehicle is running, the device asks again. Arizona calls this the rolling retest, “a breath alcohol test that is required of a person at random intervals after the motor vehicle is started”, and Colorado’s definition has the device “periodically” require additional breath samples “during vehicle operation”, and not allow the vehicle “to be started or to continue normal operation” above the set level (C.R.S. § 42-2-132.5(9)(a).)

Virginia writes out what happens when a retest goes wrong. Its rolling retest “triggers the sounding of the horn and flashing of lights” if the reading exceeds 0.02 percent or if the driver fails to take the test, and the device must electronically log the reading at every ignition, attempted ignition and retest (Va. Code § 18.2-270.1(A).)

The camera

South Carolina requires every certified device to “capture a photographic image of the driver” at the test, and makes obstructing or obscuring the camera lens a form of tampering (S.C. Code § 56-5-2941(Q)(2), (M).) Washington leans on the same images when deciding whether the device can come off: a start attempt at 0.04 or more is excused only if a test within ten minutes reads below 0.04 and the digital image confirms the same person gave both samples, and a missed random retest only if the image shows the driver was not in the vehicle (RCW 46.20.720(4).) Arizona lists “the intentional disruption or blocking of a digital image identification device” among its forms of circumvention (A.R.S. § 28-1301(2).)

What it records, and who sees it

The log goes to whoever supervises the restriction. In Virginia the offender gives the alcohol safety action program a printout at least quarterly showing every ignition, attempted ignition and rolling retest and any attempt to tamper, and the system must be monitored and calibrated at least every 30 days (Va. Code § 18.2-270.1(B), (F).) South Carolina has the device inspected every 60 days and a report prepared of the alcohol reading at each start attempt and running retest, and what the device records is a record of the Department of Probation, Parole and Pardon Services (S.C. Code § 56-5-2941(H)(1), (R).) Arizona has the manufacturer report tampering, missed compliance checks, attempts to drive above the presumptive limit and each failure to complete three consecutive rolling retests in a drive cycle, and the driver must prove compliance and calibration every 90 days (A.R.S. § 28-1461(A), (B).)

Two provisions run the other way. Minnesota’s commissioner may not require location tracking, or let it be switched on, without a court order (Minn. Stat. § 171.306, subds. 2(a), 3(g).) South Carolina must purge the photographs no later than twelve months after the person completes the program, unless an appeal or hearing is still pending (S.C. Code § 56-5-2941(R).)

The same device, four different mechanisms

Start here, because almost everything else follows from it. A driver who thinks the judge controls the device, in a state where the department imposes it, will ask the wrong person.

Why the mechanism decides the clock

Colorado is the clearest illustration. It does not order a device as part of a sentence; it restricts the license, and section 42-2-132.5 runs that restriction from reinstatement. So the interlock period in Colorado begins when the revocation ends, and a driver who waits before reinstating has not started the interlock clock at all. In Texas, by contrast, article 17.441 can put a device on the car before there is a conviction to appeal.

Virginia counts from the day the court issues the restricted license, and stops counting when that license expires until the Department of Motor Vehicles issues its own (Va. Code § 18.2-270.1(B).) Washington stops the clock for any stretch with no device installed — for incidents on or after June 9, 2016, and absent a finding that the person cannot operate one because of a physical disability — and gives day-for-day credit for time a device was on every vehicle the person drove, counted from the date of the incident (RCW 46.20.720(3)(g), (5).)

How long, by state

The terms this site has read for each state, in one table. The range is wider than most summaries suggest — from a court-set term of up to six months to life, in South Carolina for a fourth or later conviction and in Minnesota for a criminal vehicular homicide with two or more prior incidents.

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What the device is actually set to

This is the number that surprises people, and it is worth knowing before the first morning you have to blow into one. The device is not calibrated to the offense threshold. Four of the ten states write 0.02 into the statute; Florida writes 0.025 percent; California states its threshold for the rolling retest rather than the start-up one; and Texas, Arizona and Colorado write no number at all.

Ignition interlock violations: driving without it, tampering, failed tests

The common assumption is that driving a car without the device is a breach of probation. In the states that write it out it is a separate offense, and in five of them a violation also lengthens the device term.

The sentence for driving unequipped in Washington is served consecutively with any sentence for the DUI itself, and the employer exception is an affirmative defense the driver must prove (RCW 46.20.740(2), (3).) In South Carolina no part of the minimum sentence for driving unequipped may be suspended, and a first or second offense may be tried in summary court (S.C. Code § 56-5-2941(K)(2), (3).) Florida’s revocation attaches to the license rather than the sentence (Fla. Stat. § 316.1937(5)(a).) A person without a license who is convicted of one of the four acts in the table below pays $250 to $500 per violation, and if the person cannot pay, the fine becomes a lien against the vehicle that was used (Fla. Stat. § 316.1937(5)(b).)

Failed tests are violations too

A violation does not need a traffic stop. In South Carolina, Washington, Minnesota, Colorado and Arizona the device’s own record can lengthen the term, and South Carolina puts a number on each kind:

Four or more points bring a notice that the license will be suspended unless the driver asks for a contested case hearing before the Office of Motor Vehicle Hearings within 30 days; asking stays the suspension but not the device requirement. Fewer than four points can be appealed only to an administrative hearing officer within the probation department, whose decision is final (S.C. Code § 56-5-2941(H)(6), (I).)

Washington lists what blocks removal: an attempt to start at 0.04 or more, a missed or failed random retest, a missed service appointment, or removal of the device by anyone but a technician certified by the state patrol, in the 180 days before release (RCW 46.20.720(4).) Minnesota extends the device period, after treatment, for any reading of 0.02 or higher until the person shows abstinence for the full applicable period, with credit for half the time already served (Minn. Stat. § 171.178, subd. 8(e).) Colorado adds twelve months after the existing restriction if the monthly reports show the device stopping the vehicle for excess breath alcohol in three of any twelve consecutive reporting periods (C.R.S. § 42-2-132.5(7)(d).) Arizona’s list of circumvention includes bump-starting the vehicle, a false or filtered breath sample, blocking the camera, continuing to drive after the device detects alcohol above the presumptive limit, and letting someone else blow (A.R.S. § 28-1301(2).) The manufacturer reports these to the department, and the department adds six months when it has reasonable grounds to believe one of the listed events happened (A.R.S. § 28-1461(E).)

The employer exception, where it exists

Six of the ten states have an employer exception this site has read, and no two draw it the same way. In California, Georgia, Colorado and Arizona this site has not read one and therefore does not state one. If the question matters to your job, it is worth asking a lawyer in your own state rather than reading across from another state.

Motorcycles

California’s interlock section is the only one read for this page that keeps a restricted driver off a motorcycle: Vehicle Code section 23575.3(o)(5) says a person subject to an interlock restriction shall not operate a motorcycle for the duration of the restriction. South Carolina goes the other way and excepts mopeds and motorcycles from the device requirement (S.C. Code § 56-5-2941(A)(1).) Minnesota reaches past the road: a participant may run an off-road recreational vehicle or a motorboat only if it has an approved device (Minn. Stat. § 171.306, subd. 3a.) What each state’s interlock law says about motorcycles reads the rest, including Washington’s rule on motorcycle endorsements.

Ending the term: early, on time, or not until the record is clean

A few of these states write a route out. Arizona’s and Colorado’s turn on the device’s own record; Texas’s and Virginia’s on a finding by the court; South Carolina’s on an application decided for good cause. Washington and Minnesota write the reverse: a minimum that does not end until the record is clean.

Arizona — deferral after six months

For a first conviction carrying the twelve-month term, section 28-3319(H) has the department defer the remainder, starting from the later of six months after installation or completion of the listed requirements, where all six conditions apply: the person was sentenced under section 28-1381(I), completed an alcohol education program of at least sixteen hours, kept a functioning device and met section 28-1461, did not attempt to drive at 0.08 or more two or more times during the restriction, was not in an accident causing injury or property damage at the time of the offense, and the providers have sent the department the compliance information. The deferral is permanent unless the person is arrested for a DUI offense during it (A.R.S. § 28-3319(H), (I).)

Colorado — four clean months

For a first-offender who took the early-reinstatement route, the restriction can come off once the monthly monitoring reports show four consecutive periods with no lockout for excessive breath alcohol and no tampering, provided there are no other reports of circumvention or tampering and no grounds for the twelve-month extension (C.R.S. § 42-2-132.5(4)(a)(II)(B).)

Washington — 180 clean days, then an inspection

The restriction stays until the interlock vendor files a declaration that none of the listed incidents happened in the 180 consecutive days before release, and a technician certified by the state patrol has inspected the device at the end of that period and found no tampering (RCW 46.20.720(4).) So the one-, five- or ten-year minimum is the earliest the device can come off, not the date it does.

Minnesota — 90 days without a positive reading

The commissioner will not restore full driving privileges until the device has registered no reading of 0.02 or higher in the preceding 90 days, on top of the treatment and the years the ladder requires (Minn. Stat. § 171.306, subd. 4(e).)

South Carolina — a lifetime term can be reviewed

Five years after reinstatement, and every five years after that, a fourth-or-later offender reinstated under section 56-1-385, or a person with a lifetime requirement from a conviction on or after October 1, 2014, may apply to the Department of Probation, Parole and Pardon Services for removal. The department may, for good cause shown, tell the DMV the person is eligible (S.C. Code § 56-5-2941(J).)

Texas — removal for good cause

Where a court grants an occupational license with an interlock, it orders the device to stay on for the whole suspension unless it finds good cause for removal and that the device is not necessary for the safety of the community (Tex. Transp. Code § 521.246(d).)

Virginia — at the front end

For an adult first offense, a court may on the offender’s motion set the minimum at six consecutive months without an alcohol-related violation instead of twelve, if it orders additional restrictions for the life of the restricted license (Va. Code § 18.2-270.1(C).) An offender outside that first-offense rule may move for a remote alcohol monitoring device as well; with one, and a device on each vehicle, the court may issue a restricted license to drive for any purpose (Va. Code § 18.2-270.1(E).)

In California, Georgia and Florida this site has not read a statutory early-termination route, which is not the same as saying none exists. It means we have not read one.

What the statutes say about cost

Installation, monthly monitoring and removal all cost money, and the statutes generally put it on the driver. No statute read for this page sets the price of the device, so no price appears on it; any figure quoted as “the cost of an interlock” is a market estimate rather than a legal one. What the statutes do set are fees on top of it, shares of the cost by income, and help for people who cannot pay.

For the cost-and-provider side of the same requirement, our sister site covers the states it has read:

• Texas — device cost and providerssr22finder.com, written around the SR-22 filing
• California — device cost and providerssr22finder.com, written around the SR-22 filing
• Georgia — device cost and providerssr22finder.com, written around the SR-22 filing
• Florida — device cost and providerssr22finder.com, written around the SR-22 filing
• Arizona — device cost and providerssr22finder.com, written around the SR-22 filing
• Washington — device cost and providerssr22finder.com, written around the SR-22 filing
• Minnesota — device cost and providerssr22finder.com, written around the SR-22 filing
• Virginia — device cost and providerssr22finder.com, written around the SR-22 filing

Common questions

What is an ignition interlock device?

A breath-alcohol tester wired into a vehicle’s ignition. The driver blows before the engine will start and again at random intervals while driving, and the device will not let the vehicle start if the reading is over its set level. Arizona’s statute defines it as a fuel-cell breath analyzer meeting the NHTSA specifications and connected to the ignition system. Of the states on this page that write a level into the statute, four — Minnesota, South Carolina, Virginia and Washington — set it at 0.02.

How does an ignition interlock work?

Two tests. A breath sample before the engine starts, then rolling retests at random intervals once the vehicle is moving. In Virginia a retest that reads above 0.02 percent, or one the driver skips, sounds the horn and flashes the lights, and every test is logged electronically. South Carolina’s devices photograph the driver at each test. The record is checked on a schedule: the system is monitored and calibrated at least every 30 days in Virginia, inspected every 60 days in South Carolina, and proof of compliance and calibration goes to the Arizona department every 90 days.

How long do I need an ignition interlock?

It depends on the state and on the count of priors, and across the ten states on this page the statutory terms run from a court-set term of up to six months to life. California runs up to six months, then 12, 24 and 36 by prior count, and up to 48 for an injury DUI. Washington is at least one year, then five, then ten, by prior restrictions. South Carolina is six months, two years, three, then life. Minnesota runs from two years to life by priors and harm. Virginia is at least twelve consecutive months without an alcohol-related violation, or six for an adult first offender, on motion, with added restrictions. In Washington the device comes off only after 180 clean days, so the minimum is not the end date.

What blood alcohol level does the device lock at?

Far below 0.08, where the statute states one. Minnesota, South Carolina and Virginia set the device at 0.02, and Washington at 0.020 unless a court sets its own level. Florida’s start-up level is 0.025 percent, and California fails a random retest above 0.03 percent. Texas writes no number: the device makes operation impractical if ethyl alcohol is detected.

What counts as an ignition interlock violation?

More than driving without it. Washington will not remove the device if, in the last 180 days, there was a start attempt at 0.04 or more, a missed or failed random retest, a missed service appointment or a removal by an uncertified technician. South Carolina scores retests by the reading — half a point from 0.02, one from 0.04, two from 0.15 — adds months at two and three points and suspends the license at four. Minnesota extends the term for tampering, for driving an unequipped vehicle and for breaking the program guidelines; Colorado adds twelve months for lockouts in three of any twelve monthly reports; Arizona adds six months for, among other things, failing three consecutive rolling retests.

Can the device be ordered before I am convicted?

In Texas, yes, and routinely. Code of Criminal Procedure article 17.441 has a magistrate order a device as a condition of release for a second or subsequent DWI and for the listed first offenses, and the magistrate may decline only on a finding that it would not be in the interest of justice. Washington has a pretrial version too: the department restricts the license when a court imposes a device as a condition of release, until the court authorizes removal or a later department restriction for the same incident replaces it.

What happens if I drive a car without one?

In the states that write it out, it is its own offense rather than a breach of the sentence. Washington and Minnesota make it a gross misdemeanor and Colorado a class 1 traffic misdemeanor. In South Carolina a first offense carries a fine of at least $1,000 or up to a year, the third is a felony, and each conviction lengthens the device term. Florida’s interlock section does not name driving unequipped as an offense; it punishes tampering, blowing for someone and lending an unequipped vehicle.

Can I drive my employer's vehicle?

In six of the ten states this site has read one, on conditions that differ. Texas (for an occupational license), Florida, Washington, Minnesota, Virginia and South Carolina each have an employer exception. Virginia’s needs the court’s express permission at the employer’s request and never covers a school bus or commercial vehicle; Washington’s does not cover a company car used only for commuting; South Carolina’s generally excludes the self-employed. This site has not read one in California, Georgia, Colorado or Arizona, so it does not state one.

Can the term end early?

In a few states. Arizona defers the rest of a first-offense twelve-month term from the later of six months after installation or completion of the requirements, if every condition in section 28-3319(H) is met, including no two attempts to drive at 0.08 or more and no crash causing injury or damage. Colorado lets a first offender on the early-reinstatement route off after four consecutive clean monthly reports, if there are no other tampering reports and no grounds for an extension. A Texas court may order removal on good cause and a finding that the device is not needed for community safety, and a Virginia court may set an adult first offender’s minimum at six clean months on motion. South Carolina lets a fourth-or-later offender, or a person with a lifetime requirement from a conviction on or after October 1, 2014, apply for removal five years after reinstatement and every five years after that. Washington and Minnesota run the other way: the device stays past the minimum until the record is clean.

Does the device take pictures or track my location?

Pictures, in several states. South Carolina requires a photograph of the driver at each test and treats covering the lens as tampering; Washington relies on a digital image to confirm who blew, and Arizona treats blocking the camera as circumvention. Location, not by default in Minnesota: the commissioner may not have location tracking switched on without a court order.

Who pays for it?

Generally the driver, and no statute read for this page sets the price of the device. Several set fees on top: $21 a month in Washington, up to $30 a month in South Carolina, and $20 to the clerk in Virginia. Several set help for people who cannot pay: California has manufacturers charge by income, from 10 percent of the cost at or below the federal poverty level; South Carolina’s fund can cover installation and standard use; Washington has a revolving account; Colorado has an assistance program; Minnesota requires a discounted rate; and Texas and Florida let the court weigh ability to pay.