The Tunnel Hranjen project (5556.90m) in Bosnia and Herzegovina involves developing significant infrastructure on the Sarajevo–Goražde section. The tunnel is designed for vehicular speeds of up to 100 km/h, following the principles of the New Austrian Tunneling Method (NATM) for its construction. It comprises a main and parallel service tube for emergency evacuation and maintenance operations, interconnected by 21 cross passages. Sixteen passages are for pedestrian evacuation, and five are for service and emergency vehicles. Additionally, there are five parking niches on each side of the main tunnel tube for emergency stops and maintenance activities. Excavation of the tunnel began in 2019 under a contract governed by the FIDIC Yellow Book guidelines to ensure compliance with international construction and project management standards. The entrance and exit portals incorporate galleries to facilitate snow removal vehicle access during adverse weather conditions. The project required careful consideration of geological conditions and tunnel support systems, a task we undertook with confidence thanks to our use of advanced technologies such as Building Information Modeling (BIM) for integrated project planning and coordination among multidisciplinary teams. Continuous monitoring systems were implemented to track ground movements and structural responses, allowing for real-time adjustments to support measures in accordance with NATM principles, further demonstrating our commitment to innovation and efficiency. Environmental impact mitigation strategies have been integrated into the project design, addressing issues such as groundwater management, dust and noise reduction, and proper disposal of excavated materials. The Tunnel Hranjen project represents a significant engineering endeavor that enhances regional connectivity between Sarajevo and Goražde while maintaining high technical excellence and safety standards. Once constructed, it will be the longest road tunnel in Bosnia and Herzegovina.