A new MADD report puts the lifesaving numbers into sharp relief, even as drunk driving deaths have climbed 17 percent since 2019. The math is stark: since 2006, ignition interlock devices have blocked more than 5.7 million attempts by alcohol-impaired drivers to start their vehicles. In 2025 alone, the devices stopped more than 336,000 attempts — roughly one every 95 seconds — by drivers whose breath alcohol concentration registered at or above .08, the legal limit in 49 states.
Yet despite two decades of evidence, half the country still has laws weak enough to allow convicted drunk drivers to avoid installing these devices entirely.
Those are among the central findings of a new report released today by Mothers Against Drunk Driving. The organization graded all 50 states, the District of Columbia, and Puerto Rico on the strength of their ignition interlock laws, and the results are not flattering. The national average grade: failing. Twenty-four states and Puerto Rico received an F.
“MADD has long recognized that technology can play a vital role in preventing impaired driving before it happens,” said MADD CEO Stacey D. Stewart. “Each prevented start represents a drunk driving crash that may never happen, an injury that may never occur, or a life that may never be lost.”
How the Devices Work — and Why the Gaps Matter
An ignition interlock is a small breath-testing unit wired into a vehicle’s ignition. Before the engine will start, the driver must blow into the device; if alcohol is detected above a preset threshold, the car simply won’t start. Rolling retests — required at random intervals while the vehicle is in motion — prevent a sober third party from providing the initial breath sample on a driver’s behalf.
The technology has been commercially deployed for decades, and the research supporting it is consistent. According to MADD, ignition interlocks reduce repeat DUI offenses by 67 percent, and states that require the devices for all convicted offenders see drunk driving deaths drop by 26 percent.
The problem is that many states create off-ramps that let offenders avoid installation altogether. A driver can simply wait out a license suspension period — never installing a device — and eventually have full driving privileges restored. Other states exempt first-time offenders, or allow a BAC test refusal to sidestep the interlock requirement entirely.
These are the loopholes MADD’s report targets directly.
The Grading Criteria
MADD evaluated each jurisdiction on five policy benchmarks. The first and most fundamental is an all-offender requirement: every convicted drunk driver, including first-time offenders, must install an interlock before unrestricted driving privileges are restored. The second closes the “wait-out” loophole, requiring participation in an interlock program as a condition of license reinstatement rather than merely one option among several.
The third criterion is compliance-based removal — meaning a device cannot simply be uninstalled after a fixed period, but only after a driver demonstrates a sustained record of sober operation. The fourth allows a driver to begin using an interlock immediately after arrest or conviction, rather than serving a hard suspension with no driving at all, which can create financial and employment hardships that make compliance less likely. The fifth requires drivers who refused a BAC test at the time of arrest to complete an interlock program before regaining full privileges.
Who’s Leading, Who’s Failing
Eleven states and the District of Columbia earned an A: Arizona, Arkansas, Colorado, Connecticut, Delaware, Kansas, Maryland, New Mexico, Oklahoma, Tennessee, and Washington.
At the other end of the scale, 24 states and Puerto Rico received an F. The list includes some of the country’s most populous states — California, Texas, Florida, Pennsylvania, Ohio, Michigan, and Georgia among them — meaning that a substantial majority of Americans live in states where significant loopholes remain on the books.
The timing of the report is pointed. Drunk driving deaths nationally increased 17 percent between 2019 and 2024, a trend that has persisted even as vehicle safety technology has advanced substantially and overall traffic fatalities have drawn increased federal attention.
The Policy Argument
MADD’s legislative ask is straightforward: every state should require ignition interlocks for all convicted drunk drivers, including first-time offenders, for a minimum of six months. The organization frames interlocks not primarily as punishment but as a practical mechanism that allows offenders to continue working and meeting family obligations — while ensuring they do so sober.
Interlock data from manufacturers and service providers, collected on a state-by-state basis, underpins the report’s numbers. That granular data also reveals the practical consequence of weak laws: states with more loopholes show lower device utilization rates, meaning more convicted impaired drivers are back on the road without any technological accountability.
The report acknowledges that law enforcement, prosecutors, and highway safety administrators share responsibility for outcomes — good laws still require rigorous implementation. But the legislative foundation, MADD argues, has to come first.
“Strong ignition interlock laws save lives,” Stewart said. “States that require these devices for all offenders and close existing loopholes are taking meaningful steps to prevent repeat drunk driving and protect everyone on the road.”
The full report, including state-by-state grades and interlock stop data, is available at madd.org/ignition-interlocks.