It runs on a different elevation and has a more even slope, thus avoiding the steep ascending gradient to the tunnel of the old track. From Kaiserslautern Hauptbahnhof to the abandoned Gelterswoog station the line is located within the boundaries of the urban district of Kaiserslautern and from Karlsthal to Schopp in the district of Kaiserslautern. Between Steinalben and Pirmasens Nord it runs through the district of Südwestpfalz, while the remainder of the line is located on the territory of the city of Pirmasens. In the first decades most passenger trains ran between Pirmasens and Biebermühle and some of them continued to Zweibrücken. After the opening of the Biebermühle–Waldfischbach section, the two parts were operated as separate sections. After the closing of the gap in 1913, there were seven continuous train pairs, one of which ran over the Donnersberg Railway ("Donnersbergbahn") to Mainz and one via the Zeller Valley Railway ("Zellertalbahn") to Darmstadt. In addition, there were trains running between Pirmasens and Waldfischbach and between Kaiserslautern and Schopp. Improved performance in the 1930s led to two express train pairs on the Pirmasens–Kaiserslautern–Mainz route, one of them continuing to Frankfurt am Main. Express trains ran through to Darmstadt, Frankfurt and Wiesbaden in the 1960s. During the same period through coaches from Tübingen ran on the line. At the end of the 1990s, the excursion trains ended and from 1991 onwards there were no further through coaches. The last had been running to Dortmund since the end of the 1970s. Since the beginning of the 1990s, the single-track Biebermühl Railway has been operated together with the Alsenz Valley Railway, the Kaiserslautern–Enkenbach railway and the Bingen–Bad Münster section of the Nahe Valley Railway under time table number 672. There were continuous connections between Bingen and Pirmasens from 1990 to 2008. The trains usually cross in Waldfischbach at the symmetry minute shortly before the full hour. The journeys between Pirmasens Hauptbahnhof and Kaiserslautern are designated by the Verkehrsverbund Rhein-Neckar as line "R65" and those between the two Pirmasens stations are designated "R55" (Landau–Pirmasens) and "R68" (Saarbrücken–Pirmasens).