Tax cuts and government subsidies aimed at spurring auto sales have fueled a surge in traffic as China passed the U.S. last year to become the world’s biggest car market.

via Beijing Imposes Limits on New Passenger Vehicles to Reduce City Congestion – Bloomberg.

China has greater than three times the population of the Unted States. Several factors are at play. The first is the rapid growth in the Chinese economy. The second is the severe recession that knocked U.S. new car auto demand to around a 10 million unit sales pace from what was 16 million just a few years previously.