Suplacu de Barcău Viaduct, Major transportation bridge in Suplacu de Barcău, Romania.

The Suplacu de Barcău Viaduct is an unfinished viaduct on the route of the future A3 Transylvania Motorway, crossing the Suplacu basin 76 km from Oradea in Bihor County, north of the Western Carpathians. It is a traditional piled structure designed as 45 spans of 40 m over a length of 1.8 km, built from 88,000 m³ of concrete and 360 pre-cast U-beams of 160 tonnes each.

The viaduct lies on the planned route of the A3 Transylvania Motorway between Suplacu de Barcău and Borș, 76 km from Oradea in Bihor County. About 90% of its course was built before the American company Bechtel abandoned the remaining section. Work later resumed with foundation and piling activities, followed by pier construction.

The viaduct is known in Hungarian as Berettyószéplaki völgyhíd, a name tying the structure to the valley it crosses near Suplacu de Barcău. Its route lies on the planned A3 Transylvania Motorway between Suplacu de Barcău and Borș, about 76 km from Oradea in Bihor County, north of the Western Carpathians. The crossing is a recurring reference point in local discussion of the motorway's unfinished section.

The viaduct is not open: it is a construction site on the future A3 Transylvania Motorway, and the remaining section was abandoned by Bechtel after about 90% of the route was built. Access is limited to construction crews working on foundations, piling, pile caps and pier heads. The nearest reference point is Suplacu de Barcău, 76 km from Oradea in Bihor County, between Suplacu de Barcău and Borș.

The viaduct's 45 spans of 40 m each rest on a traditional piled structure, and its deck will need 360 pre-cast U-beams weighing 160 tonnes apiece. The figures come from the A3 Transylvania Motorway project, on which the American company Bechtel abandoned the remaining section. About 90% of the route was already built.