The quote describes a natural or man-made barrier, specifically an earthen berm, situated close to a set of train tracks. This berm likely serves as a visual or sound barrier, or perhaps for safety or aesthetic purposes. The presence of the berm beside the tracks helps to define the environment and context within the scene.
In James Patterson's book Hope to Die, such details contribute to creating a vivid setting that immerses the reader. The mention of the berm hints at the location's characteristics and adds depth to the scene, enhancing the story's realism and atmosphere.