By Jordan W. Charness

A few years ago, I wrote a column about little black boxes that were installed by automobile manufacturers in many new vehicles. These boxes recorded various types of information about how a car was functioning just prior to an accident, and could include the speed the car was travelling at the time of the collision, as well as when, and if, brakes were applied. What made it newsworthy at the time was the fact that the police were attempting to introduce black box recordings as evidence in a criminal trial.

In that case, the judge allowed the data collected by a black box to be used as evidence to help convict a dangerous driver, but it was not the sole evidence that was used to obtain the conviction. Other physical evidence such as skid marks and forensic reports were also used to determine the guilt of the accused.

The case made headlines and I gave dozens of interviews on radio and TV where I expressed my view that black box evidence should not really be used in a criminal trial for the simple reason that black boxes were not designed with a view for providing legal evidence, but rather, were designed to provide the auto manufacturer with data about how well specific systems are functioning in their vehicles.

Just recently, a number of organizations that I belong to, including the Canadian Transport Lawyers Association and the American Association for Justice (formerly called The Association of Trial Lawyers of America), have revisited the topic and took a careful look at what exactly black boxes can and cannot do.

To begin with, not all black boxes are created equal, nor are they necessarily even black. Each auto manufacturer designs these boxes for their own use. They usually come in two types: Electronic Control Modules, and Event Data Recorders, or Electronic Data Recorders (ECM or EDR).

They are about the size and shape of a clock radio, and have been installed in many cars and trucks since the early 1990s. The main purpose of an ECM is to control all of the engine’s operations and is like an onboard computer. Virtually all modern cars have some sort of ECM. In addition to controlling the engine, most of these also collect and store some information about what the car was doing at a given time. This information is usually downloaded by a qualified person who knows what he or she is doing and has the appropriate passwords and hardware. In general, ECMs record mainly maintenance engine faults, but some manufacturers also include some engine usage records and even hard braking data.

EDRs, on the other hand, may contain and record a lot more information about what the car was doing just prior to an accident. The original reason for installing EDRs was to make sure that airbags were properly deploying in case of an accident, and to generally use the data to build safer cars.

Now, several years after the introduction of EDRs, both defense lawyers and prosecutors are trying to use this data to prove their cases.

Unfortunately, there is no legislation requiring manufacturers to install EDRs, much less requiring them to accurately contain or record any type of information. The information recorded in an EDR of one manufacturer may emphasize completely different areas than another. Some may have accurate indications of when the brake pedal was deployed before an accident, and others may not. Some may accurately record the speed of a car at the time of an accident and some may not record speed at all.

A recent issue of the American Association for Justice’s Trial Magazine details many of the differences and shows why EDR evidence may not be accurate enough to provide testimony to convict you of dangerous driving or other vehicle crimes.

Some U.S. states, most notably California and North Dakota, are looking at passing legislation that would make it illegal to use EDR data as evidence in court unless there was a specific court order requiring it or the parties agree to use it.

So now, a few years after my original article appeared, I maintain my opinion that the data collected by EDR units should rarely be used in court since they were simply not designed to be used as court evidence.