Complex sentence: Reasons for this shift include a belief that dependency on automobiles is ecologically unsustainable; automobile-oriented environments engender dangerous conditions to both motorists and pedestrians, and are generally bereft of aesthetics.
Split into simpler sentences: Reasons for this shift include a belief that dependency on automobiles is ecologically unsustainable. Automobile-oriented environments engender dangerous conditions to both motorists and pedestrians, and are generally bereft of aesthetics.