The Georgian S1 route (Georgian: ს1, also known as Tbilisi-Senaki-Leselidze), is a "road of international importance" with a registered length of within the Georgian classification system, which makes it the longest Georgian highway route. It runs from Tbilisi via Mtskheta, Gori, Khashuri, Zestaponi, Kutaisi, Samtredia, Senaki, Zugdidi, Sukhumi and Gagra to the border with Russia near Leselidze at the northwestern tip of the country, covering in practice . After crossing the Georgia–Russia border in breakaway Abkhazia, the highway continues to Sochi and Krasnodar as A147. It is part of European E60, E97 and E117 routes and Asian Highways AH5, AH81 and AH82, and connects with six other S-routes.
North of Zugdidi, across the Enguri River which is the disputed Abkhazia–Georgia border, the remaining of the S1 route through breakaway Abkhazia is not under central Georgian control. Crossing into Abkhazia from Georgian controlled territory (and vice versa) is not possible by car, only by foot via the which is part of the S1 route. The road reaches its highest point of above sea level at the southern portal of the Rikoti Tunnel, which opened in 1982. This is the longest vehicular tunnel entirely within Georgia and has a length of .
While the majority of the S1 highway is a two-lane road, major parts have been rebuilt since 2006 as 2x2 motorway/expressway, specifically Tbilisi to Surami () and Zestaponi (Argveta) to Samtredia (). The redesign of the trunk section of the S1 between Tbilisi and Samtredia to motorway or expressway standards is part of the East-West Highway project, a major investment into Georgia's international road connectivity. As of 2021 the mountainous "Rikoti Pass Road" and the remaining of the Khashuri Bypass are under construction as 2x2 expressway and are expected to be completed by 2023.
Background
In the 1980s the current S1 route was entirely part of the Soviet M27 highway route that ran from Baku via Tbilisi to Novorossiysk. The Russian part of that M27 existed until 2018 when it got renumbered as A147 highway. Prior to the 1980s, the route of the current S1 was composed of the 17 (Tbilisi to Samtredia) and the 19 (Samtredia to Leselidze) highways.
After Georgia regained independence in 1991, the M27 designation was maintained until 1996 when the current route numbering system was adopted. In the 1996 ordinance "Indicators and List for Determination of International, Domestic and Local Roads of Georgia" the S1 route was recorded as the "S1 Tbilisi - Senaki - Leselidze (Russian border)" with an original length of . Since, the route has been shortened by to due to realignment of the road.
The S1 has been a two lane highway prior to the inception of the East-West Highway project in 2005, with the exception of Tbilisi city and the subsequent along Mtskheta to the S3 junction near Natakhtari which have been multilane since earlier years. In the 1980s expansion of the (then M27) highway to four lanes was envisioned and ground works had already started until Igoeti when the Soviet Union collapsed and Georgia became independent. This and the turbulent 1990s in Georgia interrupted these plans, which were picked up again after the 2003 Rose Revolution. Around 2004 the junction with the S3 highway near Natakhtari was upgraded with grade-separation.
East-West Highway
Since 2006 more than of the S1 highway has been realigned and upgraded to expressway or motorway standards within the internationally sponsored East-West Highway project which was initiated in 2005. This ambitious long term project aims to create a east-west transport corridor through Georgia and connecting Azerbaijan and Armenia with Turkey by upgrading Georgian sections of the E60 (Poti-Tbilisi-Red Bridge, Azerbaijan) and E70 (Poti-Batumi-Sarpi, Turkey) highways to strengthen Georgia's position as South Caucasus transport hub. The East-West Highway project includes redesign of major sections of the Georgian S1, S2, S4, S12 and more recently the S7 highway, to grade-separated highways, mostly as 2x2 expressway.
The majority of the East-West Highway has been planned as 2x2 expressway, in some cases the upgrades have been implemented as grade-separated two lane highway with median separation and hard shoulders (reminiscent of a super-two), such as the S2 Kobuleti and Batumi Bypasses. The S1 Kutaisi Bypass was initially constructed as a grade-separated wide two lane highway with hard shoulders, but was doubled to a 2x2 motorway a few years later. While most of the involved sections of the S1 have been completely redesigned and rerouted with bypasses of cities and towns, the Natakhtari to Gori/Sveneti section follows the original route and has been doubled between 2006 and 2009 by constructing an additional parallel two-lane road (and rehabilitation of the old road before becoming operational as 2x2). The northern bypass of Gori (Sveneti - Ruisi) was the first real test of the project during 2009-2011, with two new parallel 880 meter viaducts and two parallel tunnels of 800 meter in one project divided over three tenders. The short but fierce 2008 Russo-Georgian War had a temporary effect on the project, and construction quickly picked up in 2009.
Despite earlier political promises the East-West Highway would be finished by 2020, the construction of crucial sections is still ongoing (as of 2021) until at least 2024, with remaining sections of the S1 to be completed by 2023. The project is sponsored by both European and Asian development banks, the World Bank, European Union and others, giving credits amounting to more than $2 billion for the S1 upgrades alone (with additional state funding). Construction companies from various European and Asian countries have been involved, with mixed success. Some tenders ran into technical and legal issues, with some contracts having been terminated by the Georgian government due to excessive underperformance of the contracted party, resulting in multiple year delays on various lots.
For the S1 highway the (E60/E70) East-West Highway project is scoped to the Tbilisi - Samtredia section. The project envisions to upgrade the S1 to (2x2) expressway/motorway standards until Samtredia, where the S12 will continue as (2x2) motorway in the direction of Batumi. As it stands, the S1 between Samtredia and Senaki will remain a two lane highway with no major redesigns scheduled as of 2021. The focus of the East-West Highway upgrades in the western part lies in the shorter route to Batumi via a completely redesigned S12. By 2021, over of the S1 between Natakhtari and Samtredia has been upgraded to 2x2 motorway standards, with the remaining additional being under construction.
Below a detailed overview of S1 sections that have been or are being upgraded to 2x2 expressway/motorway configuration within the East-West Highway project, in consecutive order from East (Tbilisi) to West.
Segment Lot Length Funding Contractor StartConstruction Finishedor opened Remarks Natakhtari - Aghaiani 16 km State budget($40 mln) Caucasus Road Project (GE)ZIMO LLC (GE) Mar 2006 Oct 2006 Eastbound lane opened in bidirectional mode Dec 2007 Westbound lane opened in 2x2 mode. Aghaiani - Igoeti 12 km World Bank via IDA($19 mln) Caucasus Road Project (GE)ZIMO LLC (GE) Jun 2007 Nov 2008 Igoeti bypass viaducts completed in 2011 Igoeti - Sveneti 25 km World Bank via IDA($55 mln) Ashtrom Group Ltd (IL) 2008 Jun 2009 Eastbound lane opened in bidirectional mode Nov 2009 Westbound lane opened in 2x2 modeSveneti - Ruisi Lot-1 80-85km 5 km World Bank via IBRD($147 mln)State budget $37 mln Akkord (AZ)Jul 2009 Oct 2010 Lot-2 85-86km 1 km Akkord (AZ) Nov 2011 Liakhvi River Viaduct (2x 877 m) Lot-3 86-95km 9 km Todini Costruzioni (IT) Nov 2011 Including Gori Tunnels (2x 800 m) Ruisi - Agara (Mokhisi) 19 km World Bank via IDA($43 mln) China Nuclear Industry23 Construction Co (CN) Aug 2012 Dec 2015 Agara (Mokhisi) - Zemo Osiauri Lot-1 Gomi Bypass 7 km World Bankvia IDA & IBRD($55 mln) Copri Construction (KW)Black Sea Group (GE) Feb 2015 Jun 2016 Lot-2 Agarebi - Zemo Osiauri 5 km Copri Construction (KW)Black Sea Group (GE) Nov 2017 Opened for traffic on 22 Aug 2020 together with connecting Khashuri Bypass (Lot-1)Zemo Osiauri - Chumateteli(Rikoti Tunnel East portal) Lot-1 Zemo Osiauri - Surami 8 km EIB(€49.5 mln) Sinohydro (CN)Sept 2017 Aug 2020 Lot-1 was put in operation together with the above Lot-2 Agara - Zemo Osiauri (13 km in total). On 8 October 2020 the 2nd bridge across the Surami-Tsotskhnara road was opened. Lot-2 Surami - Chumateteli 6 km World Bank via IBRD($140 mln) Astaldi (IT, 2017)Sinohydro (2020) By 2019 the contract with Astaldi was terminated, which led to an arbitration case. Sinohydro won a renewed tender procedure in 2020. Construction resumed in 2021, to be completed by March 2023. Rikoti Pass Tunnel renovation 2 km World Bank via IBRD($28 mln) State budget $7 mln Sinohydro (CN) Jul 2010 Nov 2011 Including renovation of 4km Tunnel Bypass road (Sh56)Rikoti Pass road(Chumateleti-Argveta) F1 Chumateleti-Khevi 12 km World Bank via IBRD($160 mln)EIB (€76 mln)State budget $44 mln CSCEC (CN) Oct 2019 Includes 22 bridges and 3 tunnelsSecond parallel Rikoti Tunnel (1800m) F2 Khevi-Ubisa 12 km ADB ($300 mln)World Bank ($140 mln)State budget $130 mln Hunan Road & BridgeConstruction Group (CN) May 2019 Includes 35 bridges and 20 tunnels F3 Ubisa-Shorapani 13 km EIB (€332 mln)State budget €20 mln CRBC (CN) May 2019 Includes 27 bridges and 18 tunnels F4 Shorapani-Argveta 15 km ADB ($278 mln)State budget $89 mln Guizhou HighwayEngineering Group (CN) April 2021 Includes 14 bridges and 12 tunnels. Initially to be financed by Japanese JICA. Contractor was signed in Jan 2020, work began in spring 2021 Argveta - Samtredia Lot-3 Argveta-Nakhshirghele(Argveta-Kutaisi Bypass) 15 km JICA ($212 mln)Takenaka (JP) andTodini Costruzioni (IT) Jun 2013 Jun 2017 Argveta to Nakhshirghele (2x2 lanes) Lot-1 Nakhshirghele-Ukaneti(Kutaisi Bypass) 17 km Feb 2012 Nov 2014 Initially built as 2 lane road. Opening in 2014 together with 15 km of Lot-2 until exit at Bashi. In 2018 a combined project of lots 1 and 2 was initiated to double highway to 2x2. Lot-2 Ukaneti-Samtredia(Kutaisi bypass-Samtredia) 24 km Nov 2012 Jul 2016 Initially built as 2 lane highway, opening in 2016 of remaining 9 km Bashi - Samtredia. Lot-1 + Lot-2 second trackNakhshirghele-Samtredia 41 km State budget $73 mln Black Sea Group (GE, 3 lots)Akkord (AZ, 1 lot) May 2019 Dec 2020 Doubled original lots 1 & 2 to 2x2 motorway with parallel road on south side. 1.000 km = 0.621 mi
Route The Georgian "Law on motor roads" stipulates that the reference point for the mileage of roads leaving Tbilisi is Freedom Square. This means Freedom Square is the reference point of the S1 mileage reflected in the tables below (and the kilometer posts along the road) while not necessarily its actual starting point, which is a bit harder to determine precisely. The speed limit on motorway sections is and on highway sections, with the exception of passage through towns and villages (, may vary locally) and within the Tbilisi city limits ().
Tbilisi — Khashuri
Starting in Tbilisi the S1 runs north along the right bank of the Kura (Mtkvari) river in a 2x3 lane configuration with a speed limit of . As central city thoroughfare this is a crowded section, with jamming on parts throughout the day. After passing the Saburtalo neighbourhood on the left hand side, the road diverts from the river bank with a wide median and 2x4 lanes. The speed limit is here. Along the Dighomi neighbourhood the median is used for U-turn points. After passing the Tbilisi Mall at the northern tip of the city and the tight left turn to Mtskheta, the road leaves the city of Tbilisi and becomes a 2x2 expressway/motorway.