In front of JR Shibuya Station, there is a famous crossing called Shibuya Scramble Crossing. Instead of letting pedestrians cross the street one direction at a time, it closes all motor traffic and have people cross the intersection any which way they want.
This has actually reduce the traffic slowdown because there is no pedestrian when the cars are moving. Following the success of the scramble crossing, there are other cities created this crossing like England, NewZealand, Canada and the US.
When you visit Tokyo, make sure to visit Shibuya. You might want to have a cup of coffee at Starbuck looking down on this Shibuya Scramble Crossing.