The Belgrade bypass (Serbian: ? , romanized: Obilaznica oko Beograda) is a U-shaped, 69-km long motorway of which some 45 km is the section of A1 motorway (currently under construction) and the rest is planned eastern prolongation of A3 motorway. It partially encircles the city of Belgrade, the capital of Serbia.
The construction of the bypass started in 1990 and its parts have been sporadically built ever since. Its completion is expected to help alleviate Belgrade's traffic congestion, and remove all transit traffic from the city itself.
Section B is 37.2 km long part of A1 motorway that will intersect with A2 motorway at future Sur?in interchange. It is currently under construction, with some 12.7 km of in service, another 14.9 km are partially in service (one carriageway opened to traffic), and on final 9.6 km construction is set to begin in 2018. It spans the hilly terrain to the south of Belgrade, and will eventually include 4 tunnels and 40 viaducts when completed, nine of them over 400 m long, with dual carriageway Ostru?nica bridge across the Sava. It is divided in 6 sectors:
Sector B1: Dobanovci interchange - Sur?in. It includes Sur?in interchange and Sur?in south interchange with A2 highway which is under construction. Right carriageway of this 7.8 km long sector was opened in 2005, while left was opened in 2016.
Sector B2: Sur?in - Sava bridge. Right carriageway of this 4.9 km long sector was opened in 2005, while left was opened in 2016.
Sector B3: Sava bridge - Ostru?nica. This 4.1 km long sector includes 1950 meters long bridge over Sava river and Ostru?nica interchange with road 26 for Belgrade center and Obrenovac. Right carriageway was opened in 2005, while left one is under construction.
Sector B4: Ostru?nica - Orlova?a. On this 7.7 kilometers are tunnels "Lipak" (665 meters) and "?eleznik" (699 meters) and Orlova?a interchange with road 22 for Belgrade center and ?a?ak. Only right carriageway was constructed in 2008, while construction of left one is pending.
Sector B5: Orlova?a - tunnel "Stra?evica". It includes tunnel "Stra?evica", longest one on Section B (772 meters). Only 3.1 km of right carriageway was constructed in 2012. Construction of left one is pending.
Sector B6: Tunel "Stra?evica" - Bubanj Potok. Construction of this 9.6 kilometers long sector is planned. It will include tunnel "Beli Potok" (around 330 meters) and interchange Avala. It, and also section B, ends at interchange Bubanj Potok, which now exists, but needs to be upgraded.
|B1 (Dobanovci - Sur?in)||7.8 km||In service (since 2016)|
|B2 (Sur?in - bridge across the Sava)||4.9 km||In service (since 2016)|
|B3 (bridge across the Sava - Ostru?nica)||4.1 km||In service (one carriageway, since 2005) / Under construction (second carriageway)|
|B4 (Ostru?nica - Orlova?a)||7.7 km||In service (one carriageway, since 2008) / Under construction (second carriageway)|
|B5 (Orlova?a - tunnel "Stra?evica")||3.1 km||In service (one carriageway, since 2012) / Under construction (second carriageway)|
|B6 (Tunnel "Stra?evica" - Bubanj Potok)||9.6 km||Under construction|
Table's current progress status is as of April 2018.
Section C is planned 21 km long eastern prolongation of A3 motorway (which itself will connect Belgrade with Pan?evo and Vr?ac and eventually Romania at border crossing near Vatin). This is the most complex section of the bypass, as its construction involves building a 1,190-metre-long (3,900 ft) bridge over the Danube, and additional 11 viaducts and 2 tunnels. Its exact route is not decided yet, nor the start of the construction.