A device that shuts down a vehicle's engine if the driver has been drinking reduces the chances that chronic drunken drivers will be rearrested for alcohol-related traffic violations, a University of Maryland at College Park study has found.
The study, released yesterday and funded by the Insurance Institute for Highway Safety, was the first in the nation to investigate whether an ignition-interlock system has an effect on repeat offenses among randomly selected drunken drivers.
It found that just 17 out of 698 repeat drunken drivers who had the $700 interlock system installed on their vehicles' ignition systems committed alcohol-related traffic violations over a one-year period beginning in 1992.
But 46 of those in a control group of 689 repeat offenders without the device had alcohol-related violations in the same period of time.
"This shows that the device does work," said Allan Williams, a vice president for research at the Insurance Institute. "The goal now is to find if it will work when it comes off of the vehicle."
Participants in the study were randomly selected from drivers who had committed two or more alcohol-related traffic offenses in the preceding five years, or three or more offenses in the preceding 10 years. The drivers sought to have their licenses reinstated.
A second phase of the study -- to see how the 698 drivers who had the device perform behind the wheel without it -- will be released in mid-September.
The interlock system, used in about 35 states, resembles a microphone and contains a Breathalyzer. It is attached to the dashboard and wired into the ignition system, halting the engine if a driver, who exhales into a plastic mouthpiece for five seconds, registers a blood alcohol level of .025 percent or higher.
In Maryland, a driver is considered "under the influence" if the blood alcohol level is .07 percent and "intoxicated" if the level is .10 percent or above.
Repeat drunken driving arrests are a problem on the nation's roads -- of the 1.4 million arrests annually for driving while under the influence of alcohol, one-third are repeat offenders, said Julie A. Rochman, director of communications for the Insurance Institute.
In Maryland, there were 3,651 alcohol-related traffic convictions by repeat offenders last year, said Jim Lang, a spokesman for the Motor Vehicle Administration. In 1995, alcohol was blamed for 35 percent of the 683 traffic fatalities and 7,767 injuries.
Other states have reported successes with the interlock system. In West Virginia, where a program began with 787 drivers in July 1993, the rearrest rate for current and past participants is about 1 percent.
In Maryland, in addition to those who participated in the study, 551 drivers were ordered to install the ignition interlock system in their cars last year by the MVA's Medical Advisory Board.
Judges and the MVA's administrative judiciary unit also have jurisdiction to impose the system on repeat offenders seeking to have a license reinstated, said Lang.
State Del. Phillip D. Bissett, an Anne Arundel County Republican, applauded the study yesterday. Bissett, a fan of the ignition lock, last year sponsored legislation allowing the MVA to offer interlock as an option to DWI offenders seeking license reinstatement.
"This just goes to prove what we've been saying all along," Bissett said. "I am absolutely convinced that this shows that this device will get drastic results -- like saving lives."
Pub Date: 4/24/97