D4 motorway (Slovakia)

D4 Motorway
D4 Motorway
Diaľnica D4
	Completed Under construction Planned
Route information
	Part of E58
Length	48 km (30 mi) Completed: 32 km (20 mi); Planned: 16 km (9.9 mi)
Major junctions
From	A6 border with Austria
	D2 Bratislava - Jarovce; R7 Bratislava - South; D1 Bratislava - East (U/C); D2 Stupava;
To	S8 border with Austria
Location
Country	Slovakia
Regions	Bratislava Region
Major cities	Bratislava
Highway system
	Highways in Slovakia;

D4 motorway (Slovak: Diaľnica D4) is a Slovak motorway which, when completed, will form the outer ring road around Bratislava, speed up access to motorway networks and partially reduce traffic on the road network in the catchment areas of Bratislava. The D4 is one of Europe's largest public-private partnership (PPP) projects.

For decades, there was only a short stretch from Austrian border at Jarovce to the junction with D2 (part of the former D61), construction of which started in 1996 and was opened in 1998.

Construction of various other parts started in the late 2010s, with several openings throughout 2020 and 2021. The extension to the motorway D1 in Bratislava is underway, in order to connect the southern bypass of Bratislava to the country's main traffic artery. The outer ring road also intersects with expressway R7; parts of which are already open as well.