​I have defined it as a four-component system.  It creates value in space by connecting people and stuff from one place to another.


The four components are:
1. Infrastructure - may be a dirt path, airport runway or lock and dam system
2. Vehicle - may be shoes, rocket ship or a train
3.  Operator - AI can try, but someone has to feed the AI too
4.  Fuel - this is where it gets interesting!  Physics demands it; business and politics leverage that demand

So, let's think of some modes of transportation: walking, skating, segwaying, scootering, rip-sticking, bicycling.  Those all sound good.  What do they have in common?  They move a single person under their own power (accept some scooters and bicycles use electric motors to supplement the human fuel source).

Okay, let's get real.  Transportation is divided into two big categories: people and stuff.  Let's just consider people movers.  We have: cars, busses, trains, boats and planes.  (If you are thinking boats are obsolete, you have not had the privilege of using a ferry such as the one in Galveston, Texas where a bridge cannot be economically justified, or marine traffic is too complex to navigate a bridge.)

Now, of those modes consider the four components of Transportation:

• Infrastructure
• Vehicle
• Operator
• Fuel

I could write much more, but this is where you think.  My work is done for now.