It’s Time to Rethink the Driver’s License Test.

If a driver with a blood alcohol content (BAC) of twice the legal limit is a better driver (based on objective measures) than another sober driver, should the first one be allowed to drive? Common sense would dictate no, but common sense would also dictate that the sober driver should also have their license revoked.

In the age of big data, is the whole system far more generic than it can be or should be? The basic concept of the driver’s license system is that come a certain age a driver can earn a permit or a license to start learning to drive, and then take a final test with an instructor before given full permissions. This differs slightly depending on location, but generally, that is the drill. And it was necessary up until this point because there was no simple way to make the test specific and results immediate.

However, in neither the written test nor the road test does the current system objectively test for the autonomic response capacity of a driver. It is almost completely subjective – a physical observer will ride with a learner and deem based on his or her observation if the driver knows how to lane change, do a three-point turn or stop at a red light. But this is based solely on his or her observation. In a system like driving that is set with hard and fast rules, this test can and should also have an objective measure. After all, a proper parallel park has specific parameters.

An impairments to a driver’s abilities on these objective measures that have largely led societies to outlaw drunk driving. As they should – drivers with a BAC of 0.08 are three times more likely to get into an accident than a sober driver. At BAC of 0.10, that number is close to five times more likely[i]. And the reason a drunk driver is more likely to get into these situations is because a drunk driver has a slower reaction time and loses spatial awareness compared to a sober driver. They also have impaired memory, perception, and lack the same judgement and self-control as a sober individual.

But if those are the reasons we outlaw drinking and driving, logic would dictate that before we allow someone to earn their driver’s license they should pass a series of tests that ascertain the individual’s reaction time, ability to track moving objects and spatial awareness just as they have to pass an eye test for their vision.

Consider the statistics. Someone who consumes 2 units (80 mg) of alcohol in 5 minutes was 0.20 seconds slower to react[ii] when tested 40 minutes later, according to one UK study. This could be very dangerous if driving at 65 mph, or in a neighborhood where children can pop out right in front of you. The experiment (among others) also recognize a wide variance in reaction times between participants. It stands to reason that the results for sober individuals would vary widely as well, and therefore there should be an objective threshold to meet before earning a license.

But what is the acceptable limit for these tests? One suggestion is to take the average of a large sample of current drivers with licenses and use that as a baseline. Another would be to use the safe amount of time it would take to stop properly in a typical driving scenario (such as “on a highway 10 meters behind the car in front of you”, or “in a neighborhood at 30 mph”). At the testing centers, you could include tests for reaction time, spatial awareness, object recognition and evasive maneuvering on a simulated machine and require a ‘pass’ before progressing to the road test. Today’s access to high quality computing and data accelerates governments’ ability to administer a test to drivers to study autonomic responses and include that in their driving tests. It would also allow states to customize computer tests based on the typical terrain, weather, and potential risks of the area. Yes, this may exclude a few more people from earning their license. But driving is a privilege after all, not a right.

Of course, this may all be moot. If autonomous driving is ubiquitous in ten years, would the state even need a driving test? Contrary to what some might expect, these kinds of tests would be more important going forward. As autonomous driving becomes more prevalent, it will most likely tackle the easiest driving scenarios and terrains. This would leave to humans the need to drive themselves through bad weather conditions, areas with poorly marked roads, poor lighting, and weather and terrains that vary from the standard grid-like patterns of some cities. In such a case it becomes paramount that only the best drivers are allowed a license as they will lose the day to day experiences to autonomous driving. It would not be a quick change, but we would all be better for it.

[i] February 2015 US DOT NHTSA Traffic Safety Facts Research Note

[ii] https://www.ukessays.com/essays/sciences/alcohol-reaction-time.php