Reduced gasoline consumption. Enhanced viability and desirability of the transit system, as well as reduced car trips. Reduced car speeds. Enhanced viability for downtown retail. But when we take into account the area-wide impacts and changes in behavior that occur when we do things like widen roads, we find that the emperor is wearing no clothes.
Transportation is truly a zero-sum game.
Nearly always, when we make it easier to drive a car, we make it harder to travel another way. This profoundly modifies behavior and helps explain why bigger roads make things worse. We should not be fooled into the self-fulfilling prophecy that we are all doomed to live a life of extreme car dependence, wherein we are forced to make every trip, no matter how trivial, by car. For example, there are currently more cars than people in Alachua County, and each car needs approximately 7 parking spaces to which it is driven. Dover likens it to an addiction to narcotic drugs.