Historically, cities have been shaped by their urban mobility systems. Most pre-industrial cities formed along the paths of horse-drawn vehicles. A few, such as Amsterdam and Venice, were planned around canals for boats. With the invention of the electric locomotive in the 19th century, cities expanded with streetcar suburbs. In the mid-20th century, the mass adoption of the car fueled suburbia and its car-oriented buildings, such as regional malls surrounded by expansive parking lots.
