The article fails to follow the logical process to the very end. What isn't being asked is: why are humans using that road when they weren't using the smaller road before?
Humans don't just drive for the sake of doing so. They drive because they have the need to do so. Building roads lowers the perceived time cost of driving, so more people drive, and more people drive at the time that is most desirable to do so. In some cases this results in increased congestion, but if the need of the population is met or exceeded, then the result is smooth traffic flow. Even if the bigger road is more congested, it may still have a greater net traffic flow, and that increased flow results in greater economic and societal good.
For example, because of new highway XYZ, I can now work somewhere that was formerly too far a commute.
The problem isn't solved by building smaller roads, it's solved by building even bigger roads, or building roads in a more optimal fashion (selecting a route for a new road that matches the transportation needs of the population).
Humans don't just drive for the sake of doing so. They drive because they have the need to do so. Building roads lowers the perceived time cost of driving, so more people drive, and more people drive at the time that is most desirable to do so. In some cases this results in increased congestion, but if the need of the population is met or exceeded, then the result is smooth traffic flow. Even if the bigger road is more congested, it may still have a greater net traffic flow, and that increased flow results in greater economic and societal good.
For example, because of new highway XYZ, I can now work somewhere that was formerly too far a commute.
The problem isn't solved by building smaller roads, it's solved by building even bigger roads, or building roads in a more optimal fashion (selecting a route for a new road that matches the transportation needs of the population).