Ignition Interlock Devices Effective in Reducing Deaths?

Ignition interlock devices (IIDs) are designed to prevent impaired drivers from driving their vehicles. They require that the breath sample be free of alcohol before the vehicle’s engine will start. But are ignition interlock devices effective in reducing deaths from traffic crashes?


interlocks effective
Ignition Interlock Device (IID)

Researchers explored that question. Some states require IIDs on the cars of all those convicted of drunk driving.

They looked at the traffic crashes related to alcohol death rates. Then they compared of states with and without such laws. There were 18 states with these laws and 32 without them. The researchers used federal agency data.

The effects of the laws were clear three years after they started. The alcohol related traffic death rates in states with the laws was 4.7 per 100,000 drivers each year. For the states without the laws, the rate was 5.5. That’s a 15% advantage by states with the law.


There are many problems with IIDs. Someone other than the driver can blow into the sensor. The devices don’t actually measure blood alcohol concentration (BAC). They only estimate it. The devices are subject to much error. These factors can harm individual drivers. Yet the IIDs are be effective in reducing alcohol traffic deaths related to alcohol.

The researchers drew a logical conclusion. “Interlocks are a life-saving technology that merit wider use.”

Ignition Interlock Devices Effective in Reducing Deaths?


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