Ace & Lawrence have pegged it. If you believe you can still do it, I can attest that it can be done. I hot-shot (24' flatbed FL60) with my own authority. If it weren't for my wife taking up the slack in the billing/collections dept, I'd make less money, 'cause I'd be looking for loads, plus all the office work. (She also does local loads in our small truck)
Before you even consider jumping out on your own, you must have a local base of potential customers. Before I committed, I visited most all of the businesses, in my area, that I thought could possibly use my services. Stressed honesty & timely delivery. It was still three weeks after I started, that I got my first local customer's load. They are still using me. You can find loads thru brokers, by using a load board. I subscribe to DAT & getloaded.com. It is very hard to make *good* money using broker services. They must get their customer a good deal, or they're out of business. I use them for back hauls/partials only. They do have their usefullness.
Know what you want. I thought I wanted to have many trucks. At one time, I was running 6, two were T/Trailers. But, I came to the realization, that I like to drive, not sell services for a larger company. So, as I lost drivers, I sold the truck. Set up two of the drivers with their own O/Op business. 2003 was the first downsized year, and my net was within 10% of what it was when I had all the trucks.
Many things to think about. You must explore & make up your own mind. I have never regretted my decision.
Dennis