This city has a slew of traffic problems, and some solutions are more obvious than others. Many of these involve undoing wrongs of the 1960s and later. Also, think East-West. Me, I'd love to see new subway lines built, because thinking long-term helped a century ago. But short-term trams will help a great deal. Its all politics and budget fights now, and things are improving slowly.
The New York Times has a title story today that gives some insights.