Isolation is a big one. When you're on a road trip, you can be in the middle of nowhere. For example, if your car breaks down in a desolate area, like in the desert or a remote forest, and there's no immediate help. It makes you feel vulnerable.
Strange encounters are also terrifying. Meeting people or things that seem otherworldly. Like in some stories where travelers meet a strange figure on the road that gives them an uneasy feeling or does something unexplainable. It plays on our fear of the unknown.
The idea of being lost. In a road trip horror story, getting lost can lead to all sorts of terrors. You might end up in a place that has a bad reputation, or you could be going around in circles with no way out, and as time passes, your resources run out and your fear builds up.
Getting lost is very common. You might follow the wrong GPS directions or misread a map, and end up in an unfamiliar and potentially dangerous area.
Running out of gas in the middle of nowhere is a typical family road trip horror story. You're happily driving along, not paying close enough attention to the gas gauge, and then suddenly the car sputters to a stop. You're miles from the nearest gas station, and it could be hours before someone comes along to help. And then there are the stories of car problems that mechanics can't seem to figure out easily. You're stranded at a garage for days while they try to diagnose and fix the issue.
Unnatural occurrences are terrifying. Like when the weather suddenly changes in a very abnormal way, from a clear sky to a thick fog in seconds. Or when the technology in your car, such as the lights or radio, starts acting up without any logical explanation.
Strange encounters are often very frightening. Meeting strange people on the road who act oddly or seem menacing. For example, I heard a story where a traveler was followed by a car for miles and the people in it were making strange gestures. Another scary part can be staying in creepy places like old, haunted - looking motels where you feel like something is not right. You might hear unexplained noises or see things that give you the creeps.
Strange encounters are a big part of the horror. Meeting odd - looking people in the middle of nowhere, or having animals act in an unnatural way. For example, a deer that doesn't run away but just stares at you with glowing eyes. And then there are the stories of phantom vehicles that seem to follow you or disappear suddenly. These elements make horror road trip stories truly frightening.
One horror story is when a person on an LSD trip thought they were being chased by shadowy figures that seemed to be emerging from every corner. They ran until they were completely exhausted, and it turned out to be just hallucinations caused by the drug.
Isolation also plays a major role. Take 'The Lighthouse' for instance. The two lighthouse keepers are isolated on a small island, and as strange things start to happen, they have no one to turn to. The sense of being alone in the face of the unknown is very frightening.
The most terrifying element is often the unknown. In many of these stories, like in 'The Tell - Tale Heart', the narrator's unhinged mental state is not fully understood. We don't know exactly why he is so obsessed with the old man's eye, and that mystery adds to the horror. Also, in 'The Monkey's Paw', the power of the paw and how it will exact its price is unknown, which scares us.
A terrifying story is about the haunted oases. There were rumors that some oases along the Silk Road were haunted. Travelers who stopped there at night might hear strange noises, see apparitions, and feel an eerie presence. Some said it was the spirits of those who had died in the desert, unable to find peace.
In my opinion, 'The Call of Cthulhu' is one of the most terrifying. It involves an ancient, otherworldly being that drives people mad just by the knowledge of its existence. It's a Lovecraftian horror that plays on the fear of the unknown and the cosmos.