Every car hauler is required to carry insurance, just like you and me. The difference is, the carrier's insurance covers all the cars on the truck too. The three main things to be concerned about for insurance on trucks are liability, cargo, and deductible. The insurance will cover damages in the event of driver's negligence. In most cases, it won't cover an act of God, or some such thing. Just like on a personal auto, liability covers damages to others property. Imagine a wreck that is bad enough to take down a bridge. There should be enough insurance coverage so that the company doesn't go bankrupt having to replace it. Don't use any company that has less than a $1 million liability coverage.
Cargo is the one to be most concerned with. It covers all the vehicles in the event of loss. A decent amount of coverage is $300,000. This is the total amount to be paid out. So if there are 10 very expensive vehicles on the carrier, someone is not getting compensated enough.
The deductible is just like what you'd carry on your Jeep. A $1,000 deductible is low and what you want.
One of those gray areas is if your vehicle is dropped off at a terminal to juggle vehicles or change trucks. Many companies won't cover damage to a vehicle while it's at a terminal. If you are going with the lowest bidder (most use a terminal), be sure to see in writing that any damage anywhere on the trip to your Jeep will be covered. If it isn't in writing, with damage at a terminal specifically mentioned, move on.