"One goal of Smart Growth is to move our society away from dependence on cars, and many Smart Growth plans intentionally make it difficult to drive through the neighborhood, making walking more inviting. Smart Growth planners advocate short blocks in a grid pattern to distribute traffic (vehicular and pedestrian) evenly within a development. These short blocks produce a multitude of 4-way intersections, and add a multitude of those trendy "turnabouts," to make a bland site plan look more interesting.
But all of this together destroys 'flow'. On the other hand, in a grid planned neighborhood you might drive a straight line with an occasional turn, giving the impression of a much shorter drive than a curved subdivision. But with short blocks, a driver must stop completely, pause, then when safe accelerate through the intersection onto the next intersection, then repeat multiple times. This scenario uses a tremendous amount of energy; the car eats gas."