"The invention of the wheel is often put forward as a pinnacle of human ingenuity, but it strikes me that the defining characteristic of modern transportation systems is not the wheel but the pneumatic tire."

From a brief history about pneumatic tires by Scope of Work. Nearly all of today's wheeled transportation depends on the pneumatic tire. How would transportation be different if the pneumatic tire had not been invented?

Also interesting that the initial invention was before it's time. Originally the pneumatic tire was created for horse drawn carraiges, but never caught on. Only until humans were responsible for propelling themselves on bikes did the pneumatic tire gain traction as a means of providing a smoother and more efficient ride.