Belgrade bypass
The Belgrade bypass is a U-shaped, 69-km long motorway of which some 45 km is the section of A1 motorway 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.
Route
;Sector ASector A is 11.1 km long part of A1 motorway that intersects with A3 motorway at Dobanovci interchange. It is completed and opened to traffic in 2012.
;Sector B
Sector B is 37.2 km long part of A1 motorway that will intersect with A2 motorway at future Surčin interchange.
It is currently under construction, with some 12.7 km of in service, another 14.9 km are partially in service, 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 Ostružnica bridge across the Sava.
It is divided in 6 sections:
Section B1: Dobanovci interchange - Surčin. It includes Surčin interchange and Surčin 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.
Section B2: Surčin - Sava bridge. Right carriageway of this 4.9 km long section was opened in 2005, while left was opened in 2016.
Section B3: Sava bridge - Ostružnica. This 4.1 km long section includes 1950 meters long bridge over Sava river and Ostružnica interchange with road 26 for Belgrade center and Obrenovac. Right carriageway was opened in 2005, while left one was opened in June 2020.
Section B4: Ostružnica - Orlovača. On this 7.7 kilometers are tunnels "Lipak" and "Železnik" and Orlovača interchange with road 22 for Belgrade center and Čačak. Only right carriageway was constructed in 2008, while construction of left one is pending.
Section B5: Orlovača - tunnel "Straževica". It includes tunnel "Straževica", longest one on Sector B. Only 3.1 km of right carriageway was constructed in 2012. Construction of left one is pending.
Section B6: Tunel "Straževica" - Bubanj Potok. Construction of this 9.6 kilometers long section is planned. It will include tunnel "Beli Potok" and interchange Avala. It, and also section B, ends at interchange Bubanj Potok, which now exists, but needs to be upgraded.
| Section | Length | Status |
| B1 | 7.8 km | In service |
| B2 | 4.9 km | In service |
| B3 | 4.1 km | In service |
| B4 | 7.7 km | In service / Under construction |
| B5 | 3.1 km | In service / Under construction |
| B6 | 9.6 km | Under construction |
Table's current progress status is as of April 2018.
;Sector C
Sector C is planned 21 km long eastern prolongation of A3 motorway. This is the most complex sector of the bypass, as its construction involves building a bridge over the Danube, and additional 11 viaducts and 2 tunnels. Its exact route is not decided yet, nor the start of the construction.