Many jobs CAN'T be done without someone driving to a location- it's literally impossible but it's also difficult to implement public transport in smaller communities because the cost is prohibitive. Also, the US has become more of a service economy that a manufacturing economy- if it were still the latter, I think this would be much easier. OTOH, people like the freedom to go somewhere directly from their workplace, rather than riding to their car and leaving from a place that may cause its own traffic problems because of the time needed for that.
Many places could use more ride-sharing- it gets passengers to their destinations and they would/might meet new people- this is fairly common in Los Angeles, where traffic is a complete nightmare.
Having taken an urban planning class when I was in college, I can say with confidence that until recently, urban planners didn't care about energy use. They tend(ed) to care about how their vision will be seen by others.
This is very difficult to address in older, sprawling cities where existing buildings and roadways cover most of the ground.
Great idea, hard to do.
