It was different as I remembered it. Towing companies had to bid on those contracts, and you couldn't get one of them unless you could demonstrate two things: (1) you had a wide range of equipment to deal with all kinds of unusual towing jobs, and (2) you could guarantee that you'd have drivers on the road very quickly at any time of the day or night to get to the scene.
Interestingly, I never heard many complaints about removing junk cars. When a car was towed off the road it was stored in the company's own lot and immediately began accruing storage charges. Once the storage charges reached a certain point and the owner never picked it up, the towing company would get a junk title for the car. Even the salvage value of such a car almost always exceeded the cost of the tow itself (not necessarily the storage charge) by a wide margin.
It is the same here, In order to get on their list you have a whole bunch of hoops like that to jump through. But any company in a designated coverage area can get on the rotation list for that area if they jump through the hoops.
The only way to really recoup any losses from salvage though, you have to also get a dismantler’s license and/or a dealer’s license. And these are both a true pain in the ass and expensive to get. Due to land use permitting, environmental requirements, and liability insurance.
On top of it all, there is politics involved. There is so much crooked back pocket money involved from competitors it can almost be impossible sometimes unless you become crooked too. ny “bidding” that goes on is on a personal basis to state and county officials or they will stonewall you right out of business.