Do you have anyone in your family that is a truck driver, they earn a living by driving a semi truck
I actually don't, but I have a friend that does! It's a tough job. The hours are really long and driving the truck is a lot more exhausting than it looks.
Although they do provide an essential service by transporting goods and raw materials over land - 
They do. It's a very important job! Don't you need a special license to do it?
In the US, I believe they need a CDL License - and part of that is that they are responsible for inspecting their vehicle for issues related to safe operation.
Ahh makes sense. Safety is very important. I would think they needed specialized training too, parking a semi truck can't be easy!
Yes, driving commercial vehicles definitely requires advanced skills and knowledge above and beyond those required to drive a car.
Do you know how much they get paid on average? Special skills must mean decent pay...
I am not sure exactly but I think they are paid by the mile verses the trip or what they are hauling - but they also have a take breaks such as resting for 15 minutes every 5 hours, 30 minutes every 8 , etc..
Ahhh...that would explain all those rest stops that you see on the highways. That's an interesting way to get paid!