I clearly indicated the issue with the article. If there are 50,001 people at a 50,000 person stadium, you can't point to one guy and say he is the reason it is over capacity. Further, there is no one who doesn't understand that less drivers on the highway = a faster commute. But therein lies the classic unintended consequence: Whatever you do to improve the commute leads to more traffic. Twin that highway and you'll see a massive boom in suburban building, for instance.
Or we can select 1% of the drivers on the highway, call them the problem, and call it a day.
I think that the article is saying they have a disproportionate impact on traffic. They are more directionally-biased, spend more time on the road, and have a greater spatial and temporal overlap with other drivers' commutes.
All of those things apparently contribute to traffic more than people who travel in random directions at random times.
Also, it means that it is (potentially) more of a fixable problem. If you can target those specific sources and destinations of problem drivers, you can try to offer them alternatives. Even if they are replaced by other drivers, many of those other drivers may behave more randomly, and the roads will have better utilization.
You're missing the point, which is that the the maximum carrying capacity of a road is a function of the skill exercised by the drivers.
The issue revealed here is that even a small number of unskilled drivers can do terrible things to the flow of traffic on busy roads. In other words, crowded roads have a very low tolerance for bad drivers.
Since the number of disruptively bad drivers is so remarkably low, and their negative effect is so stratospherically high, a program designed to improve their skills could save astonishing sums of time and money.
So it's not about "calling them the problem and calling it a day." It's about actually fixing the problem. And you don't need to single people out to do this. Rather, you set the bar for licensing at a level that they'll need to do additional work to cross. Given how few of them there are, this can be done with no disruption to 99% of the drivers on the road, and major benefit to 100% of them.
The article specifically mentions that it's not driver skill which is the issue:
These commuters aren't necessarily slow or bad drivers.
Instead, they come from a few outlying neighborhoods and
travel long distances together in the same direction like
schools of fish -- clogging up not only the roads they
drive on, but also everyone else's.
I clearly indicated the issue with the article. If there are 50,001 people at a 50,000 person stadium, you can't point to one guy and say he is the reason it is over capacity. Further, there is no one who doesn't understand that less drivers on the highway = a faster commute. But therein lies the classic unintended consequence: Whatever you do to improve the commute leads to more traffic. Twin that highway and you'll see a massive boom in suburban building, for instance.
Or we can select 1% of the drivers on the highway, call them the problem, and call it a day.