On January 31, 2024, the Prenn pass was officially opened to traffic after nearly a year of expansion and upgrading works. In the Prenn pass upgrading and expansion project, A2Z Construction Consulting Joint Stock Company played a crucial role as a consultant for comprehensive design and surveying from the pre-feasibility to feasibility stages. The company provided solutions for roadbed expansion and rational bridge adjustments to both meet technical standards and preserve the characteristic gentle curves of the pass.
According to Decision 894/UBND-GT of the Lam Dong Provincial People’s Committee, vehicles (except trucks) were permitted to travel both directions on this pass from 8:00 a.m. the same day, with a maximum speed of 60km/h. Earlier, on December 14, 2023, the section from Datanla Waterfall to the end of the route was technically opened to traffic, alleviating traffic pressure during the peak tourism season.
Located within Da Lat city, the Prenn pass spans 11km, connects National Highway 20 with the city center. This route, winding through pine forest slopes, serves as a vital arterial road, while also being a renowned tourist attraction, featuring well-planned landscapes and services along both sides of the route.
The upgrading project was managed by the Lam Dong Province Transportation Project Management Board as the investor, the HHV-DCC joint venture handled construction, and A2Z was in charge of design consulting. The project commenced on February 10, 2023, with a total investment of 21 million USD. The upgrade includes roadway expansion from 7.5 to 14 meters to accommodate four lanes. Along the route, the slab girder bridge at Km221+800 was widened by an additional 3.5m; a new Super-T girder bridge at Km225+800, measuring 120m in length and 15.5m in width, consists of three simple spans. Sharp curves were realigned to reduce slopes and improve visibility, the drainage system and anti-landslide retaining walls were constructed comprehensively to ensure safety in all weather conditions.
The project adopted advanced technologies such as LiDAR, 3D Laser Scanning, Digital Twin, and Building Information Modeling (BIM) to digitize existing conditions, create 3D models, visualize construction, and early detect design conflicts from the outset. As the lead consultant overseeing design and surveys from the pre-feasibility to feasibility stages, A2Z proposed roadbed-widening solutions and rational bridge adjustments that not only met technical standards but also preserved the characteristic “gentle” contours of the pass.
Currently, the Prenn pass has become the widest pass road in Vietnam, significantly reducing traffic congestion and safety hazards at treacherous curves. Additionally, the new spacious, safe, and scenic route enhances the appeal of Da Lat tourism, opening opportunities for sustainable economic development for Lam Dong Province.
News: Phuong Chi
