Transportation problems will remain a focus for the years to come. Calls for increased spending on public transportation are the norm. But in the US privately owned vehicles will still be the most popular way to travel. Even if the number of people taking public transportation were to double, it would have little or no effect on the percentage of people using private vehicles - considering population growth. The only way to make public transit an effective approach to congestion and pollution control would be to make vehicles less convenient and more costly.
Approaches differ the world over.
A steep increase in gas prices or licensing fees such as in Europe would be strongly opposed by Americans, and political suicide so that remains unlikely. Consider Singapore, where drivers are not allowed into the city center without having a fee based permit. Undoubtedly rising congestion in some US cities may require such steps, but not in the near future. America is building more roads, which never seems to have much effect. The paradox is that more roads could increase the number of automobiles.