Sober to Start

Make our roads and country safer.

States requiring ignition interlock devices for first time offenders have shown a decrease in deaths caused by drunk driving. Contribute today!

What is an Ignition Interlock?

An ignition interlock is a device about the size of a cell phone that is wired into the ignition system of a vehicle. A convicted drunk driver must blow into the device in order to start their vehicle. If they have a measurable amount of alcohol in their system, the vehicle will not start. It is a simple and economical way to make sure that offenders can drive to and from work, but that they can’t drive drunk. 35 states plus Washington, DC require these devices for all convicted drunk drivers.

 

MADD supports Ignition Interlocks for All Convicted Drunk Drivers

The average drunk driver has driven drunk 80 times before a first arrest. While suspending the license of these individuals makes sense, in reality, three out of four of those with a suspended license continue to drive, threatening the safety of you and your loved ones. According to a meta-analysis of studies, ignition interlocks reduce repeat drunk driving offenses by 67%.

That’s why MADD supports the usage of ignition interlock devices to require all convicted drunk drivers to prove they are sober before the car will start.

Ignition Interlocks Saves Lives

According to the Insurance Institute for Highway Safety, laws mandating ignition interlocks for all convicted drunk drivers reduces drunk driving deaths by 16%.

Ignition interlocks Prevent Drunk Driving

According to data collected by from ignition interlock manufacturers, MADD found the these devices prevented over 4.9 million attempts to drive with a BAC of .08 or greater from 2006 to 2023 in the United States. These are people ordered to use an ignition interlock after a drunk driving offense, who were prevented from driving drunk thanks to this lifesaving device.

MADD Ignition Interlock Fact Sheets

Map of laws

Difference Between License Suspension and Ignition Interlock

Overview of Studies

MADD Data and Reports

2023 Data on Stops by an Ignition Interlock

2022 Data on Stops by an Ignition Interlock

2021 Ignition Interlock Report

2017 Ignition Interlock Report

2016 Ignition Interlock Report

What Can You Do to Help?

We need your help to require use of this life-saving technology by all offenders. Ask your representatives to require interlocks for all offenders.

Make our roads and country safer.

States requiring ignition interlock devices for first time offenders have shown a decrease in deaths caused by drunk driving. Contribute today!

Today, we can see a future without drunk driving, but we need your help to get there. Please join us in the fight by pledging to support the future of No More Victims®.

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Ignition Interlock FAQs

No. MADD advocates requiring ignition interlocks only for convicted drunk drivers with an illegal blood alcohol concentration of .08 or greater.

Alcohol ignition interlocks are required to meet standards set by the National Highway Traffic Safety Administration (NHTSA). These standards ensure that the devices are reliable.

Offenders pay for the interlocks, as they are the ones getting the benefit from it (the ability to drive legally).

On average, interlocks are about $70-150 to install and about $60-80 per month for monitoring and calibration. This is less than three dollars a day. In most states, interlock companies provide interlock devices for offenders who can’t afford the devices or an indigent fund is set up by the state to cover costs for these offenders.

This is possible, and there should be strict penalties for blowing into someone else’s ignition interlock or for having someone else blow into the device. However, interlocks are required to have anti-circumvention features that prevent such activity. One of these features is the running retest, which requires offenders to blow into the device at random intervals once the vehicle has been allowed to start. Furthermore, blowing into an interlock is a learned skill that requires specific training that would most likely be difficult for an impaired person to administer. There are also tamper-proof seals on interlocks.

This is possible. However, when someone commits a crime, he/she is responsible for the consequences of his/her actions. If an interlock is one of these consequences, then the offender is responsible for making sure those driving his/her vehicle do not drive intoxicated. State laws should also have provisions for an appeals process in which offenders can appeal failed tests.

No, the devices have temperature and air gauges to make sure this cannot occur.

Studies have shown that interlock devices decrease recidivism by about two-thirds while installed on the vehicle. When removed, these rates tend to go back to normal. This might not be the case if interlock programs were coupled with treatment and offenders were not allowed to have the device removed until they demonstrated a period of compliance. The possibility of re-offending is much greater if tests are failed during the interlock period. Unfortunately in most states, offenders still automatically get the device removed at the end of the specified period, even if they failed a test the day before. To make laws more effective, states should add provisions for treatment and extended periods for non-compliance.

Interlocks are hooked up to a vehicle’s starter system, not to the engine itself. The interlock does not have the ability to stop the vehicle once it is running for safety reasons. When a driver fails a running retest, the vehicle’s horn will honk and/or the lights will flash to alert law enforcement – the vehicle will not stop.

The tests are not designed to be done while the car is actually rolling. Interlocks give people a few minutes – enough time to pull over – to perform the retest.

Courts throughout the states have analyzed this issue and no state appellate court has overturned an interlock statute.

No, they can drive the vehicle as well; they simply must blow into the device and prove sobriety before the car will start. Having an interlock installed on an offender’s vehicle actually allows the offender and his or her family to continue to drive legally. Other sanctions like vehicle impoundment or immobilization do not allow for this.

Individuals with low lung capacities due to being ill, having asthma or pulmonary disorders are generally able to provide the needed breath sample. If they can demonstrate that they are unable, the device settings can be adjusted to account for this. Failing that, medical waivers are needed.

They can and do.  It is imperative that state laws plan for this by requiring that all cars that the offender operates, not just owns, are equipped with an interlock. Also, offenders choosing not to drive should be required to have some other form of electronic monitoring, like continuous alcohol-sensing ankle bracelets. In Hancock County, Indiana, alcohol ignition interlock installation rates increased from 20 percent to 62 percent when the alternative was electronic monitoring.  These policies alone reduced DWI/DUI rates by 40 percent for first offenders and 22 percent for repeat offenders.

Some judges do not know how they work or do not understand their effectiveness. Judicial education on this topic is so important because generally those judges who know the most about interlocks are the ones using them most.

Why?  The illegal drunk driving limit in all 50 states and Washington, D.C. is .08 BAC. Studies show that offenders with extremely high-BACs are only slightly more likely than offenders just over the legal limit to recommit the crime of drunk driving.