Who Invented the Ignition Interlock Device?

March 21, 2019

Over the past century, humanity has been forced to adapt to the widespread implementation of the personalized motor vehicle. While automobiles have played critical roles in revolutionizing transportation and pushing the world into the modern era, there have been unintended consequences to their introduction. One such issue that we as a society are still attempting to tackle is drunk driving, which, according to the National Highway Traffic Safety Administration, was responsible for nearly one-third of the 37,133 traffic crashes fatalities in 2017.

In the vast majority of states, a driver who has a DUI violation will be required to install and maintain an interlock device in their vehicle. The nationwide adoption of interlock devices has been a critical component in the fight against recidivist drunk driving, but these devices were not simply created in a vacuum; rather, they were the result of countless inventors innovating on past devices and concepts. Below, you will find a brief overview of how the initial breathalyzers and interlock systems led to the creation of modern ignition interlock systems.

Interlock Devices

Interlock devices, also known as car breathalyzers, utilize technological innovations from other inventions that had similar functionality or underlying purposes. At their essence, an interlock device is the combination of two different mechanisms:

  • A breathalyzer – A device that uses a breath sample to estimate a person’s blood alcohol concentration.
  • An immobilizer – An electronic security device affixed to the car’s engine to prevent it from running unless the transponder signal is given.

Crude versions of these tools were used sporadically throughout the early 20th century, but it wasn’t until the mid-1950s where the tech caught up to concepts.

Early DUI Laws

Prior to the advent of cars, drunkenness did not result in many negative societal externalities and accidents. A person drinking too much could do very little to harm a fellow citizen, even with horses or carriages. The introduction of the personal automobile, a heavy and fast-moving machine, changed things; in the hands of an intoxicated driver that machine became a weapon. So, as more cars populated the roads, fatal crashes caused by drunk drivers rose precipitously.

In response to this threat, New Jersey and New York became the first states to pass any sort of DUI laws.

  • New Jersey (1906) – Stated, “No intoxicated person shall drive a motor vehicle.”
    • Violation of the law resulted in a fine of $500 or up to 6 months of jail time.
  • New York (1910) – Did not stipulate an intoxication level, simply said motorists were not allowed to operate a motor vehicle while drunk.  
    • Violation of the law carried a $1000 fine.

At the time, there simply was no way to accurately gauge how much a person had drunk. As a result, these vague laws remained in effect until they were updated in the ’40s.  

The Drunkometer

The first study on measuring alcohol intoxication was published in 1927 by Dr. Emil Bogen. It was titled, “The Diagnosis of Drunkenness–A Quantitative Study of Acute Alcoholic Intoxication.” While it was common professional knowledge that testing blood gave you an indication of intoxication, Bogen took this further by testing urine, blood, and breath. He found that with the correct device, breath could reliably estimate a person’s blood alcohol content.

When the Prohibition was lifted in 1933, legislators and officials feared how it would affect the roads. Much of the public was concerned that intoxicated driving would naturally increase. To try and prevent this, the National Safety Council and American Medical Association conferred about the issue and determined that it was necessary to set a legal limit. They concluded that a driver with a BAC level of .15% or above could be considered inebriated. Although it was good to set limits, a significant problem law enforcement faced was that there was no reliable way to measure blood alcohol content in the field.

Using Bogen’s work, a University of Indiana professor of biochemistry and toxicology named Rolla Harger started tinkering with a device that would be able to measure the alcohol on a person’s breath. It would gather a breath sample into a balloon, which would be mixed with a chemical solution. If the breath sample contained alcohol, the solution changed colors. The larger the color-change, the more alcohol was present. By 1936, he patented and released his “Drunkometer” the very first practical roadside breath-testing device, and the precursor for the modern breathalyzer.

The Breathalyzer

Two decades later, another Indiana University professor named Robert Borkenstein made great strides in the field of blood alcohol concentration testing. By this point, Bogen’s “Drunkometer” was considered a crude and inaccurate device for measuring blood alcohol level. Since the device relied on infrared spectroscopy to determine BAC, invalid test results could occur depending on:

  • The temperature of the subject
  • The temperature of the device
  • The air temperature

In 1954, Borkenstein created the “Breathalyzer,” a device that would use chemical oxidation and photometry to measure BAC. The machine would take a breath sample and then measure the percentage of alcohol vapors within it. Both law enforcement and medical professionals agreed that the breathalyzer provided vast improvements to a field test’s speed and accuracy. As a result, it quickly phased out all other testing devices.

The Borkenstein breathalyzer would continue to be widely used by law enforcement for almost a decade until it too was surpassed in 1967 by Bill Dulcie and Tom Jones’ first electronic breathalyzer. This electronic model became the baseline which every future electronic measuring device would work to improve upon.  

The Invention of The Interlock Device

In 1969, the initial concept of the interlock device was developed by the Borg-Warner Corporation, a research laboratory in Des Plaines, Illinois. The Borg-Warner corporation created a working prototype that had a BAC sample tester which was able to interrupt a vehicle engines starting circuit. The device was inspired by the Immobilizer, an alarm system created in 1919 by George Evans and Edward Birkenbuel.

After the Borg-Warner device, a few critical updates were made to the concept. These include:

  • 1981 – Jeffrey Feit, a New Jersey student, participated in a statewide innovation contest. He placed thanks to his schematic concept for an interlock device that used a breathalyzer.  
  • 1983 – Hans Doren, an Irish student, participated in the Dubliner Young Scientist Competition. He presented a working prototype of Feit’s breathalyzer interlock schematic.

Thanks to these inventors, the mandatory installation of semi-conductor interlock devices became a common practice for DUI offenders. While the devices got the ball rolling, they had some key issues that detracted from their utility:

  • They did not remain calibrated for long.
  • They were sensitive to altitude.
  • They were sensitive to temperature.
  • They could give a false positive for non-alcohol contaminated samples.

By the 1990’s the practice of interlock device installation for those convicted of a DUI had been implemented across the country. The commercialization of the devices spurred innovation and the demand for improvements to accuracy and convenience. Soon, “second generation” devices were released that boasted more dependable and precise alcohol fuel cell sensors. To ensure uniform compliance, any device sold had to meet the standards set by the National Highway Traffic Safety Administration.

Modern Day Interlock Devices

Current interlock devices are required for most any person who is charged with a DUI. The violator will be legally required to have the equipment installed by a qualified technician who will link the device to the vehicle’s mechanical and electrical system.

The modern-day interlock device can be found inside the vehicle, by the driver’s seat. The device is directly installed to the engine’s ignition system and is composed of two components:

  • Handset – The part you blow into for a breath sample.
  • Relay Module – The part that connects to the handset and measures the BAC. If the BAC sample is below the threshold, the engine ignitor is allowed to fire.  

Modern devices use an ethanol-specific fuel cell sensor. When alcohol in the breath touches the catalytic electrode surface, it chemically oxidizes, sending out an electric current to the electrochemical sensor. The current is measured and converted to a BAC reading. The ignition interlock cuts the ignitor signal to the starter until a permissible breath sample can be provided.

Interlock Rolling Retests

All modern devices require that a rolling retest be taken within ten minutes of the initial breath sample. This is done to prevent a driver illegally using a sober person’s breath sample to bypass the interlock requirements. The rolling retest occurs in random time intervals, alerting the drive that a sample is required. Once the device has alerted the driver that another sample is obligatory, the driver will have 5-7 minutes to provide a sample. If the sample exceeds the limits or is not given, the device will take the following actions:

  • Log the event as a failed test, which can result in extended legal action.
  • Flash a warning.
  • Start an alarm, flashing the lights and honking the horn until the car is switched off or the test is passed.

As a note, an interlock device will not, in any situation, turn off the engine while a person is driving, since this could create far more problems than it would prevent. The warnings and alarms are meant to alert authorities that might be in the vicinity that a person has failed their rolling retest.  

Why the LowCost Interlock Device is Right For You

If you have made the unfortunate blunder of driving under the influence, it is likely that you will be required by law to buy, install, and maintain an interlock device in your vehicle if you wish to continue driving. Low Cost Interlock is a company that adheres to state laws and regulations and has a spotless record when it comes to suspensions.

The LowCost interlock device is an incredible piece of tech that provides several benefits, including:

  • Price – LCI provides a clear and detailed payment form based on your driver profile. All costs are apparent upfront, and there are zero hidden fees. LCI also offers free shipping, setup, and installation on any interlock device.
  • Easy to use – LowCost Interlock has worked to simplify the breath sample process. Many other devices require that the driver give a patterned breath sample that involves a mixture of inhaling, blowing out, and humming to provide the sample. Such an involved process is inefficient, annoying, and can lead to faulty readings. To give a breath sample with the LowCost Interlock LCI-777 device, all you have to do is blow out for three seconds.
  • Accurate – Having an interlock device is hassle enough without it giving false positives that result in a failed test. The LCI-777 uses modern technological innovation to provide the most accurate BAC reading possible. The devices are also recalibrated periodically to ensure correct readings.
  • Hygienic – Many interlock providers fail to ensure the cleanliness of their devices before they are passed on to the next owner. LowCost Interlock, on the other hand, requires that the device be sent to headquarters for a rigorous cleaning. At HQ, the device will be treated and tested for cleanliness. Once testers are satisfied, the equipment will be sent out to the next user. On top of this, the blow-out method of providing a sample makes it so you do not need to inhale what someone else blew out.   
  • Discrete – Having an interlock device can be an embarrassing symbol of your past mistakes. LCI’s standard device is meant to be as inconspicuous as possible, but for members who want even further discretion, LCI offers “The Can,” an interlock device that looks identical to a soda can. So, when you provide a sample, it simply looks like you are taking a sip from the can.
  • 24/7 Customer Support – Low Cost Interlock has 24/7 bilingual customer support and onboarding. On top of that, they have hundreds of locations spread across the country where you can have the device installed and maintained.

Wrapping Up

Interlock devices have been the product of many brilliant minds applying current technology to past innovations in order to spur improvement. Low Cost Interlock’s LCI-777 device is the amalgamation of decades of progress. So, if you are searching for an ignition interlock for your vehicle, look no further! Low Cost Interlock is just what you need.

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