University of California Transportation Center

In all of the world's cities, the most acute transportation problems of congestion, accident and air pollution are severe today and growing worse rapidly. In the US, today as many as 120 million residents live in areas with unhealthy air. Motor vehicle crashes account for 90% of all transportation fatalities and even larger percentage of injuries during the last two decades. Most of rich literatures illustrate that these severe problems in US are principally the results of excessive use of cars rather than poorly designed and operated public transportation.