My people--the Haida used to paddle up and down the northwest coast, as far west as Hawaii, and as far north as Alaska. Now we look back and think of those trips as unimaginable. Just as our means of transportation today will appear 500 years from now!
Feet were the only means of locomotion for thousands, maybe even millions of years. Who really knows how long for sure.....but these figures sound reasonable if you stop and think about it for a while. But compared to the old days, modern transportation is like a blink of an eye, in terms of technological advances. Getting around the world only takes hours instead of months. I don't think the world would function the same if the use of such "luxuries" ceased to exist! The world would be chaotic and anarchy would reign!
I don't think anyone has taken advantage of transporation technology as fully as the military. They've gone from the horse to the tank, and the tank to the air! They have developed such efficient means of transportation that the world has followed suit and--"poof"--we have modern transportation. Mind you, it took a few centuries to accomplish. Now the question is always asked "How can we make it better?" and that's where the race for the new technology begins.
Actually, it's not that bad. The companies that win the contracts for the military or other corporations have employees to worry about. It almost seems as if humans don't want to move by means of manual motive power anymore. No matter what is invented there is that question again! "How can we make it better?" Example: windows in a car door...at first they were fixed, then they were able to roll up or down, and then along comes power windows. Great if the car is running, but when the car is off, the windows don't work! So the question really is: "When will we really be happy with our transportation?"