Stephen King often appears as a cameo in his own movies/series. Here he plays the Greyhound bus driver that picks up Gina and Terry.
At Francie's safe house (Episode 7) one of the "hippies" introduces another as "Captain Tripps" That's also the name of the flu that wiped out earth in "The Stand", also by Stephen King.
Harlan and Gina Williams' malevolent pursuer, Jude Andrews (played by R.D. Call), and the Williams' protector, Terry Spann (played by Felicity Huffman), both worked for the secret US Government agency known as "The Shop" that had kidnapped Drew Barrymore in another Stephen King novel, Chamas da Vingança (1984).
While convincing Harlan and his wife to flee with her, Terry makes reference to an Agent Rainbird. This is another reference to "Firestarter."