The ratio of those two values shows, in my experience, that a lot of people are not very good at things they spend a lot of time doing, and are generally unaware of their own shortcomings
The average American spends 4.2 hours a week in the car. A typical 40 year old american has driven around 50,000 miles. For someone to continue to be bad at driving after that much experience, it must be a fundamental limitation on their capabilities for learning, thinking, or understanding. Drive to work any given day in Denver and you will see that a large number of people suffer from those fundamental limitations.
This article seems to present a world where most people the author interacts with can think critically about a complex topic, and are interested in learning or improving themselves. I wish I lived where the author lives, because I have had multiple jobs across multiple countries and never encountered an average population like the author describes.
People driving and making decisions are error prone.
A simple test is to watch how people turn. Do they turn early potentially hitting the curb or cutting it too close to pedestrians. Or do they increase their radius by turning late? The latter are better drivers.
Edit: here are more tests,
- do they signal
- do they cutoff others
- do they let those who signal in
- do they drive too slow or too fast for the given road and conditions
- do they have an awareness of all cars around them
- do they block the passing lane
- do they maintain a reasonable distance behind other cars
- do they let emergency vehicles pass
etc.