This article presents the results of more than 24 years of monitoring of displacements along a Šindliar fault plane using a high-resolution 3D extensometer (TM-71), which was installed in the Branisko highway tunnel. This significant fault, striking NNE–SSW, separates the pre-Cenozoic basement of the Branisko mountain range and Cenozoic sediments. The micro-movements indicate a contemporaneous oblique dextral strike-slip, which is consistent with regional transtension/extension proved by previous geological studies. Furthermore, obtained results show that the displacements are permanent, very slow, and reflect the changes in the stress field. An average speed of movement reaches 0.11 mm a year. Jump-like changes correspond well with weak earthquakes as well. Our results prove that cracks in the reinforcement of the Branisko highway tunnel occur as a result of recent tectonics. The long-term monitoring may contribute to the safe operation of the tunnel and represent a warning system in future.