World Resources Institute: City leaders face incredible pressure to deliver sustainable transportation. Cities now account for more than half of the worlds population--by 2050, they will hold 75 percent of us. These people--increasingly from the middle class--will need ways to commute to work, travel, and carry out their livelihoods.
At the same time, 1.27 million people die from traffic accidents every year--about half of these fatalities occur in cities. Cities also account for about 70 percent of global greenhouse gas...