The title of this thread is somewhat misleading in that the article doesn't really talk about any sort of CBD-wide ban on cars, but rather talks about the possibility of a city shutting down its main street for pedestrian use.
The list of cities that have shut down its most important thoroughfare (on weekends or permanently) to pedestrians goes on and on. Tokyo has Ginza and Mexico City shuts down the Paseo de la Reforma on Sundays. Despite all the talk about China going auto-centric, you will find in China's biggest cities that their main shopping streets have all been turned into pedestrian malls: Beijing's Wangfujing, Shanghai's Nanjing Road and Guangzhou's Beijing Road.
So the real question the article raises is whether we should bring back this: