An interview yields some interesting things for a band to consider about road managers.

Musician.com: How do you make sure the band is paid fairly?
Brenner: As an addendum to the contract, there would be a list of expenses that are agreed to between the band's management through the booking agent and the local promoter. Typically those involve things such as advertising, production sound and lights, crew costs, catering, security, box office staff, Ticketmaster, etc. Those are all pretty standard. The tour manager should always expect at the end of every performance to be presented with a list of bills from the promoter validating these figures. At a certain point you have to believe that the bills you are looking at are indeed the correct bills. You can dispute a dollar or two here or there, but if you've done it two or three times you realize it isn't a worthwhile use of your time. You need to look at the overall expenses to see if they're in-line with what was previously budgeted. So the expense side is one issue and the income side is the other issue. You need to see the Ticketmaster manifest and understand how to read it. You need to know that within the contract you'll see a number that says what the gross box office receipt is at sellout, so if there is a sellout those numbers should be close. There are always a few seats here or there. It's never an exact match, but the numbers have to be close and reasonable. The way the deal typically works in a medium sized theatre, once you've determined the basic expenses and agreed on the basic income, the promoter will get an additional 15%, which is their profit. That profit is added onto the expenses and subtracted from the income. Then whatever money is leftover is split between the band and the promoter as per the contract: 80/20, 85/15 or however that's agreed upon. And you should always walk out with your money. But it's a business and for the most part people are dealing straight up with it because it's not worth it to screw your band for a few hundred dollars when they know they've got to deal with this agent for 20 or 30 other bands that they want to book. It's not as ugly a business as it might have been some years ago.

Thanks to Rob for the tip.