There's a related paradox - I don't remember the name - that the speed of traffic is determined by the speed of public transit. Cities with less car congestion probably have faster public transit.
That doesn't seem like a paradox at all. If you have more convenient public transit then more people use it. If more people use it then there is less traffic.
This is also why things like bus lanes are ridiculous. The theory is supposed to be that making the bus faster than cars will get more people to use it. But if that actually created a benefit that exceeds its cost, i.e. got more people to take the bus than the wasted capacity of not allowing cars to use that lane when a bus isn't, then it would reduce the traffic congestion that it inherently requires. It's a thing that can't even be part of the solution to the problem because any means of actually solving the problem would eliminate its mechanism of operation.
This is also why things like bus lanes are ridiculous. The theory is supposed to be that making the bus faster than cars will get more people to use it. But if that actually created a benefit that exceeds its cost, i.e. got more people to take the bus than the wasted capacity of not allowing cars to use that lane when a bus isn't, then it would reduce the traffic congestion that it inherently requires. It's a thing that can't even be part of the solution to the problem because any means of actually solving the problem would eliminate its mechanism of operation.