Liquid-bulk tanker work for owner-operators is certainly one of those freight niches where there are many niches within the niche, if you will, as Overdrive's Partners in Business guide makes clear.

Thousands of gallons of liquid moving at highway speeds behind the headache rack can put the fear of God in a driver, says Dennis Holliday. “A lot of guys get scared” thinking about it, Holliday says.

Sean Ross is a strategic adviser at 1031x.com, Investopedia contributor, and the founder and manager of Free Lances Ltd. Shipping tends to be cyclical, though not all forms of transport are affected ...