Contrary to the video Cheonggyecheon is not Braess Praradox.

For instance "To address the consequent traffic problem, the Cheonggyecheon Restoration Project Headquarters established traffic flow measures "

"The project contributed to a 15.1% increase in bus ridership and a 3.3% increase in subway ridership"

It was a billion restoration project.

It is a good example how any superficial improvement to traffic where a road is removed is called Braess' Paradox.

Or anytime a road is added or upgraded and it gets worse for anyone, everyone says Braess' Paradox.