Urban Form and Transportation

Give us your ideas on improving how we move around the city and what shape its future growth should take.
In 1950, Omaha's population density (the number of people per unit of area) was about 6,000 people per square mile. Today, it's substantially lower - about 3,650 people per square mile. What are we doing, or not doing, with all that space? Are we hampering our ability to efficiently move around the city and provide the city services we all need and want?
The key elements in how our city is laid out - the type and location of housing, the presence of sidewalks and trails, the type and location of employment centers, the physical design of our roads - all impact the way we navigate around Omaha. We know cars are important, but we also need to make room for walkers, bikers and those who would use mass transit if it was easy and got them where they needed to go.
What can Omaha do to make better use of the space it currently occupies? What can we do to encourage the use of active forms of transportation (walking, biking, public transit)? What are you doing individually that could be implemented on a citywide scale?