Ignition Interlocks Stopped the Most Drunk Drivers in Wis. Last Year

A state-by-state breakdown of drunk driving attempts prevented by ignition interlocks shows that a total of 354,372 incidents of driving while intoxicated were averted nationwide in 2017, according to Mothers Against Drink Driving (MADD).

Wisconsin reaped the greatest benefit with 46,750 avoided drunk driving attempts, followed by Texas with 29,488, and California with 25,105. Drunk driving was defined as drivers with blood alcohol concentrations (BAC) of 0.08 percent or higher.

MADD released the data on April 11 to coincide with Iowa becoming the 32nd state to enact an ignition interlock law.

Ignition interlocks prevent a vehicle from starting if alcohol is detected on the driver's breath. Any attempt to drive while intoxicated is recorded by the device — and the results, according to MADD, prove that ignition interlocks are an effective deterrent to driving under the influence.

"We know that in 2017 alone, the potential for a drunk driver to kill or injure someone was stopped more than 300,000 times, which confirms that drunk driving is a national public health crisis," said Colleen Sheehey-Church, MADD's national president.

All-offender interlock laws reduce drunk driving recidivism by 67%, according to the Centers for Disease Control and Prevention (CDC). Moreover, a recent study by the Insurance Institute of Highway Safety found that states with laws that mandate ignition interlocks for all drunk driving offenders have reduced drunk driving fatalities by 16%.

Presently, 45 states mandate interlocks for at least certain impaired-driving offenders, and 32 states and the District of Columbia have laws that require interlocks after the first offense at 0.08 BAC or higher.