NJ DWI News: Can We Trust Breath Test-Ignition Interlock Devices to Measure Drivers’ BAC Accurately?

Based on a recent poll found on AAA Mid-Atlantic’s website, 61 percent of respondents said individuals with first-time drunk driving convictions should be required to have a breathalyzer-ignition interlock device installed on their vehicle. A larger 85 percent felt that an ignition interlock should be mandatory only for subsequent offenses. As a New Jersey DWI defense attorney, I have represented clients charged with driving under the influence of alcohol, many of whom were unjustly accused due to inaccuracies inherent with breath testing machines.

The point here is that vehicle-installed breath testing devices are not necessarily more accurate, or even as accurate as the units used by law enforcement. Yet judges are requiring many people convicted of drunk driving to have these interlock devices installed. The problem I see going forward is how accurate can the in-car units be when the validity of the more expensive and complicated Alcotest and other breath-testing machines have recently been called into question?

From the results of the AAA poll, it would appear that popular opinion is tilted against those accused of driving while intoxicated, and there is no doubt that New Jersey drivers charged with a DWI offense face rather stiff penalties. But to be judged fit to drive by a possibly less accurate machine may be a burden itself.

Earlier this year, in an effort to establish the effectiveness of breathalyzer devices, New Jersey’s Supreme Court ordered the breath testing machine manufacturer, Draeger, to give up the code that its products — such as the Alcotest device — use to determine blood alcohol content (BAC).

After two reviews, it was found that the Alcotest software was actually below quality standards and potentially unreliable. Since the Alcotest device does not directly measure a person’s blood (which, by the way, is the most accurate method to determine BAC) the machines must rely on their internal software to accurately analyze the alcohol particles present in a suspect’s breath. It was suggested that poor coding and faulty software could lead to a higher BAC reading.

Knowing this much, is it possible that the breathalyzer-ignition interlock devices have better or worse quality and accuracy? Without direct scientific evidence, it would be hard to tell, but relying on them to monitor the sobriety of convicted DWI offenders may not be the best solution. Rather than take your chances on modern technology, it’s best to employ the services of an experienced drunk driving defense attorney and possibly avoid the question altogether.