Ancient Roman roadVia Militaris connecting Balkans, central and western Europe had similar route to modern-day A4 motorway. Old highway which is still in partial use was constructed during 1960s and 1970s. Soon it was found out that there are, especially during summer season, too many vehicles which made road unsafe on some parts. So in 1990s construction of modern motorway started.
Beginning of construction
The first section of the motorway were 3 km from Trupale interchange to Komren on entrance in Niš which was constructed in the period 1990—1992. After 1992, due to the wars in Croatia and Bosnia and Herzegovina and UN sanctions towards FR Yugoslavia, construction of motorways in Serbia stopped until the wars ended. Construction of the Komren—Prosek section, which is usually referred as Niš bypass, started in 1998, but was cancelled due to the war in Kosovo and NATO intervention. Construction of this section was completed in 2006. Soon after, project of completion of the motorway started.
Construction of rest of the motorway
The first two sections on which construction started in 2010 were Pirot east — Dimitrovgrad and Dimitrovgrad bypass. Next year, construction started on Crvena Reka — Čiflik, while in 2012, construction of Prosek — Crvena Reka commenced. Finally in 2013, construction started on sections Čiflik—Staničenje and Staničenje — Pirot east. First completed section was Pirot east — Dimitrovgrad in 2016, but it could not be opened until two neighboring sections were completed. The next two completed sections were Crvena Reka — Čiflik and Čiflik—Staničenje which were opened in July 2017. In July 2017, section Prosek—Bancarevo was also completed, but it was still not opened because Bancarevo — Crvena Reka section was not completed at the time. In August 2017 first carriageway of motorway was opened of 5.1 kilometers-long part of section Staničenje — Pirot east from end of bridge Nišava 4 to Sarlah tunnel. In September of same year, for traffic were opened last 7.2 km of section Staničenje — Pirot east, section Pirot east — Dimitrovgrad and first 6.8 km of Dimitrovgrad bypass. Also, 1.2 km of half-profile motorway were opened on Dimitrovgrad bypass. In March 2018, full-profile motorway was completed on 5.1 km-long part of section Staničenje — Pirot east on which first carriageway was opened in 2017. Also were opened another 0.6 km of full-profile motorway and 0.6 km of second carriageway on Dimitrovgrad bypass. In June 2018, the last 0.6 km of the second carriageway on the Dimitrovgrad bypass was opened. In June, was also opened first carriageway on 2 km from bridge Nišava 2 to bridge Nišava 4 on section Staničenje — Pirot east, while the second carriageway on this part was opened in July 2018.
