Is There a True Solution to Suburbia?

Suburban areas came about as people wanted to have the ability to own their own homes and have their own land.  In recent years, however, it has become clear that there are some issues with the idea of suburbia.  One of them being environmental impacts.  Suburban areas tend to be more spread out, and therefore car dependent areas.  This can potentially cause a lot of pollution.  While, a dense city is notorious for being high in pollution because of the dense number of cars, there are designs that can be done such that a city does not need to be car dependent.  In my opinion that is the true issue.  Its not so much an issue of a person using a car, but rather that it is car dependent and they don't have a choice but to use a car.  But with an area that is more spread out and isolated from the heart of a city, how can you create a space that fosters walking or other modes of transportation?  Is creating small "towns" within suburbia with their own shopping and grocery stores the answer?  I am not sure that I have a real solution to this problem, but I do acknowledge that it is a flawed system.  I am one of those people who prefers not to live in a dense city and would one day want to own a home and land.  I also recently purchased a bike and would love to have a way to use it as a form of commuting instead of always having to drive.  Maybe the solution is in the infrastructure (at least as a start).  How can we create infrastructure that encourages and makes it safe to use other forms of transportation?  Having just lived in Mount Pleasant, I know they do a good job of creating safe bike lanes to where biking to work or to the beach, even if its 10+ miles away is feasible.  But that is not necessarily an example that is directly applicable everywhere.  Just something that we as architects should consider when we design and possibly talk with our city planners about.