| Overview | |
|---|---|
| Location | Mount Bolu |
| Coordinates |
Mt. Bolu Tunnel
Mt. Bolu Tunnel (Turkey)
|
| Route | O-4 E80 |
| Start | Kaynaşlı |
| End | Yumrukaya |
| Operation | |
| Work begun | 1993 |
| Opened | 2007 |
| Operator | General Directorate of Highways |
| Traffic | automotive |
| Technical | |
| Length | 2,788 m (9,147 ft) (east bound) 2,954 m (9,692 ft) (west bound) |
| Number of lanes | 2 x 3 |
| Operating speed | 70 km/h (43 mph) |
| Highest elevation | 860 m (2,820 ft) |
| Lowest elevation | 810 m (2,660 ft) |
| Width | 2 x 17 m (56 ft) |
| Grade | 1,7% |
Mount Bolu Tunnel (Turkish: Bolu Dağı Tüneli) is a 2.9 km (1.8 mi) long highway tunnel constructed through the Bolu Mountain in Turkey between Kaynaşlı and Yumrukaya.[1]
The tunnel is part of the Gümüşova-Gerede Highway O-4 E80 within the Trans-European Motorway project, which was carried out by the Turkish Bayındır and Italian Astaldi joint venture since April 16, 1993.[2] The total cost of the tunnel is about US$300 million. It has twin 17 m (56 ft) wide bores and carries three lanes of traffic in each direction.
The tunnel crosses the North Anatolian Fault. The November 12, 1999 Düzce earthquake (MW=7.2) caused substantial damage to the tunnel and viaducts, which were under construction at the time of the earthquake.[2]
On September 4, 2005 the excavation of the tunnel in the Istanbul-Ankara direction was finished. The excavation for the tunnel in the Ankara-Istanbul direction was completed by the beginning of August 2005.
The Istanbul-Ankara direction (2,788 m (9,147 ft)) was opened to traffic on January 23, 2007 by the Turkish Prime Minister Recep Tayyip Erdoğan and Italian Prime Minister Romano Prodi.[2] Four months following the initial opening, on May 7, the Ankara-Istanbul direction (2,954 m (9,692 ft)) became operational.[3]
Speed in the tunnel is limited to 70 km/h (43 mph).[4]