The short story "One for the Road" was featured in the Stephen King collection Night Shift and is a follow up to his novel 'Salem's Lot.
During the auditions, Lou DiPilla (the Gas Station Attendant) was asked if he could do a Maine accent. He said "No, but I can give it a try" and proceeded to blow the producers away by nailing it with little effort. He was the first actor on the project to be cast even before he left the building.
When Gerard (Eric Slodysko) is driving toward 'Salem's Lot, the exit sign he passes is spray painted with a red "eye" and the phrase "All things serve the beam." The eye is that of The Crimson King, the main antagonist of The Dark Tower series, the phrase is a popular saying within that universe. Coincidentally, 'Salem's Lot is one of the many interconnecting novels to The Dark Tower as Father Callaghan from 'Salem's Lot becomes a main character later on in The Dark Tower saga. This makes the story of "One for the Road" indirectly connected to those books as well.
The cover of the book "A House of Shadows" that Janey (Sandy Lawler) is reading, makes reference to other novels written by Ben Mears and also features reviews by authors from other Stephen King stories, such as Bill Denbrough (IT), Paul Sheldon (Misery) and Scott Landon (Lisey's Story).
On Gerard's GPS, the display shows that they are driving on Witcham Street towards Jackson Street. The intersections of Witcham and Jackson are where Georgie Denbrough meets Pennywise the Clown in IT.