Caliber became the new name of the parent company Roadway Services Inc. After Roadway Express went on their own, the parent company was renamed Caliber. RPS and the regionals, Viking, Spartan, Coles and Central Freight plus Roberts Express and some others were under the Caliber umbrella. There was the failed attempt to combine the services of the regionals to make a national service LTL company under the Viking name. It failed, causing the closure of Coles and Spartan and leaving Viking in the West and Central covering its original territory. At some point Central Freight was taken/bought out of Caliber and were on their own.
Fedex liked RPS and ended up buying all of Caliber to make Fedex Ground. Viking and the others were left alone for a couple years then were combined with the purchase of American Freightways to become Fedex Freight. Roberts Express became Fedex Custom Critical. A few years later, Fedex bought Watkins which became the Economy service know as National LTL, which later got folded into the Fedex Freight system.