S5 highway (Georgia)

The Georgian S5 route (Georgian: საერთაშორისო მნიშვნელობის გზა ს55, Saertashoriso mnishvnelobis gza S5, road of international importance), also known as Tbilisi-Bakurtsikhe-Lagodekhi (Azerbaijan border) or Kakheti Highway, is a "road of international importance" within the Georgian road network and runs from Tbilisi via Sagarejo and Bakurtsikhe to the border with Azerbaijan near Lagodekhi over a distance of 160 kilometres (99 mi).^[1] After crossing the Georgian-Azerbaijan border the highway continues as M5 to Zagatala and Yevlakh.

Since the early 1980s the current S5 route was referred to within the Soviet road network as A302 between Tbilisi and the junction West of Lagodekhi. Beyond this point the road was part of the A315 to Zagatala and further into the Azerbaijan SSR. Prior to the 1980s the route of today's S5 was unnumbered as was the case with most Soviet roads.^[2]

After Georgia regained independence in 1991, the Soviet route designations were maintained until 1996 when the current route numbering system was adopted. In that year the "roads of international importance" (S-)category was introduced and the "S5 Tbilisi-Bakurtsikhe-Lagodekhi (Azerbaijan border)" replaced the old A302 and A315 designations.^[3]

Referring to its main location, the Kakheti region, the road is nicknamed "Kakheti Highway". The segment in the capital region until the Tbilisi Bypass intersection has been built as a 6 lane city express road, and has been so until the airport since the 1970s. The rest of the highway was a 2 lane highway passing through towns and villages.

Between Tbilisi and Bakurtsikhe the highway was redesigned to a four lane motorway in the 2020s. In 2024 the first section of 35 kilometres (22 mi) till Sagarejo opened as motorway.^[4] To improve traffic flow in the crowded Alazani valley, a grade separated two-lane bypass road between Bakurtsikhe and Tsnori was opened in August 2024.^[5]