Radio IS in business to make money and therefore, if you can get a traffic sponsorship on the weekend, then do it! Obviously, they have sponsors. They also feed other non-CC stations with their reports. Again, the 4th largest city should be able to get sponsors for weekend traffic reports. They have a sales team there which has a presentation to back up their claims of the amount of reach they have with their reports.
By the way, KNTH does not have a relationship with Total Traffic, as it already has an established contract with Traffic dot com.