Congested streets are the result of them being managed by the government, they aren't caused by poor road design.

All roads should be privatized, and consumers should pay for them like every other good and service they use.

How do popular restaurants, sports stadiums, and every other aspect of the economy deal with massive demand and limited supply?

Raising prices, and in the long-term making capital investments to increase supply.

Street congestion should be the quintessential textbook example in Econ 101 to explain the concepts of economic shortages.

Can you imagine any other good or service whose price never changes based on demand NOT having shortages?

Imagine a concert hall that charged the same price for seats whether the Rolling Stones or Vanilla Ice is playing?

The experiment with public streets has been a massive failure, and it's time to be ended.