> If the metric was really traffic, then that could easily be solved on any road by only allowing even-numbered license numbers to drive on even-numbered days, and vice-versa.

They tried this in Beijing. People would just buy second cars so they could drive on both days. Eventually they had to restrict new license plates as well.

I don't think anyone is claiming that is literally the only metric, because if it were, you could also just ban driving completely, or kill a bunch of people, etc.

I mean, I don't see how that's really a fair response to saying what people care about is traffic. Yeah, ability to use the road, sure. I don't think people want a new highway to be built and then told they can't use it because they don't have a new car or something.

I as a motorist could not give less of a shit if I'm stuck in traffic for 3 hours a day but the road is able to move hundreds of thousands of cars a day. I'd prefer a road that could only move 20 people a day with 0 traffic. It's the only thing I care about.

why would you count that as a win? you almost certainly wouldn't be one of those 20 people allowed on the road

The example was clearly intended to include the motorist in question, being allowed to be on the road. As long as the motorist got to use the road, it wouldn't matter to said motorist how large the capacity of the road was, if they weren't able to clear through it quickly without traffic. It wouldn't matter if the road in question was servicing large amounts of people, it's only visible impact to the motorists time on the road that matters.