Shanghai taxicab drivers

Today I learned that Shanghai taxicab drivers are rated on a zero-to-five scale, using stars, with stars earned for seniority and positive customer feedback. Five is the highest ranking. Zero was the ranking of my first cab driver, and my next cab driver was rated one star. Apparently the serial number on their ID cards has meaning too: The lower the number, the better. It means they've been driving longer, and presumably will be more familiar with the Shanghai sprawl.

My one-star taxi driver in Shanghai; he drove sloooooowly.