This just in: Interlock company Smart Start is suing North Carolina’s DMV. According to the Associated Press:

“The company filed a lawsuit Friday at North Carolina’s Office of Administrative Hearings, accusing the Division of Motor Vehicles of unfairly blocking its attempts to win the state’s contract for the devices.”

The North Carolina interlock market is worth about $10 million a year. No wonder Smart Start wants in. And if legislators expand the use of interlocks to more offenders, those profits could triple. Gee, maybe that’s why Smart Start lobbies for increased use of interlocks.

But, seriously, maybe North Carolina is better off without Smart Start and its questionable business practices.

Our previous post on Smart Start brings to mind something else that interlock advocates don’t talk about much: How much trouble faulty interlocks could bring to your everyday life. Interlocks are subject to “false-positive” readings, which occur when it registers a positive reading, even though you haven’t consumed any alcohol.

To see how chaotic universal interlocks could be, look no further than interlock advocate Robert Strassburger of the Alliance of Automobile Manufacturers. In a 2008 presentation, Strassburger presents two scenarios. In the first, interlocks are assumed to be “Six Sigma” devices. Six Sigma refers to a quality management system in which a product only has 3.4 defective parts per million. In other words, assume 99.99966% of device parts are free of fault.

But even if (and that’s a big “if”) interlocks met this high standard, Strassburger calculates there would still be almost 4,000 cases of misreadings per day. That’s thousands of people trying to go to work, school, or about their business who could find their car locked down by a faulty interlock or having to file an “appeal” with an interlock company.

In Strassberger’s second scenario, interlocks are only “3 Sigma” reliable, which he defines as 2,700 defective parts per million. This would cause almost 3 million misclassifications every day, and these misreadings would outnumber the number of hypothetical DUI trips that the interlocks would stop. In other words, by this quality standard, interlocks do far more harm than good.

Today’s interlocks aren’t exactly Six Sigma quality if they’re being set off by people eating pizza and drinking coffee. Yet, MADD is looking to see interlocks—or similar alcohol-sensing technology—placed in all cars within the next 5-10 years.

Does that really seem like a good idea?

This weekend, KTVK in Arizona reported on a growing controversy involving one of the nation’s biggest interlock companies, Smart Start.

Watch the story here:

Basically, Smart Start is accused of forcing drivers to keep interlocks installed on their cars for longer periods of time by deliberately delaying the process of reporting data on interlock usage to Arizona’s Motor Vehicle Division.  The reporting delay denies drivers the opportunity to challenge the results.

The story explains that drinking coffee, eating a donut, or even a piece of pizza before driving can generate a false positive from the interlock and cause the engine to lock. And as KTVK points out, with each unchallenged false positive “drivers could be penalized and forced to keep the ignition interlock device in their cars for up to another year. That’s an extra year per violation.” And keep in mind: every offender in Arizona is required to use an interlock. Maybe not the best idea.

Obviously, Smart Start stands to benefit from its customers keeping the interlock on for longer periods of time. But, if this accusation is true, Arizonans should be outraged.

Note: This isn’t the first time Smart Start has become embroiled in a scandal or engaged in questionable practices in the name of profit.