Struma Motorway

Struma Motorway is part of the European Union priority project 7 for development of the Trans European Transport Network along the motorway axis from Igumenitsa/Patra, via Athens and Sofia, to Budapest. The motorway will provide significant improvements to the road network of South-Eastern Europe and will create conditions for enhanced cooperation between the countries in the Southern Balkans area. The motorway completion is important from a strategic point of view for the regional development and providing a direct route through Bulgaria to the Aegean Sea.

The Struma Motorway route covers part of the Trans European corridor number IV. It carries the heaviest volume of traffic of any route crossing Bulgaria in the north-south direction. The section connects six of the largest cities in the western part of the country – Sofia, Pernik, Blagoevgrad, Vratsa, Montana and Vidin.

Struma Motorway is approximately 150 km long and is divided into three sections:

  • Lot 1, Dolna Dikanya to Dupnitsa with length of 17 km;
  • Lot 2, Dupnitsa to Blagoevgrad with length of 37 km;
  • Lot 3, Blagoevgrad to Sandanski with length of 62 km;
  • Lot 4, Sandanski to the Greek border crossing at Kulata with length of 15 km.

Lot 1 is operating and Lot 2 and 4 are currently in final stage of completion. The Employer under these contracts is the Road Infrastructure Agency. The preparation activities and the construction of Lot 3 are carried out by National Company Strategic Infrastructure Projects which will be responsible for the management and maintenance of the whole route of the motorway after its full completion.

Information brochure for preparation of Lot 3 of Struma Motorway [English]


Lot 3 “Blagoevgrad – Sandanski”

The alignment of Struma Motorway Lot 3 is located within a beautiful but at the same time environmentally sensitive area. Most part of the route runs near the flood plain of the Struma River, and into the transport corridor including the existing E79 road, and the Sofia-Kulata railway. There are intersections with the E79 and other roads, as well as numerous structural crossings of roads, rivers, railway lines, water courses, etc.

The alignment crosses several Natura 2000 sites as well as the bio-corridors connecting them. The key sites are as follows:

  • Habitats site “Oranovski Gorge – Leshko” (identification code BG0001022) – situated in Lot 3.1;
  • Habitats site “Kresna – Ilindentsi” (identification code ВG0000366) – situated in the Lots 3.2 and 3.3;
  • The alignment pаsses close to the Habitats site “Ograzdhen-Maleshevo” (identification code ВG0000224) – situated in Lot 3.3;
  • Birds site “Kresna” or “Kresna Gorge” as stated in the English version of the relevant Standard Data Form (identification code ВG0002003) – situated in Lots 3.2 and 3.3;
  • Birds site “Rupite” (identification code ВG0002098) – situated in Lot 3.3.

Lot 3 is foreseen as a new dual two-lane A29 standard motorway of approximate length 62 km, and is further divided into three subsections as follows:

  • Lot 3.1, between Blagoevgrad and Krupnik, which is 12,6 km long featuring a mix of interchanges, earthworks and structures;
  • Tunnel at Zheleznitsa with length of approximately 2 km and the respective road sections and structures;
  • Lot 3.2 between Krupnik and Kresna is with approximate length of 21 km. The section runs through challenging mountainous terrain. It is dominated by a tunneled route in the Kresna Gorge, of total length approximately 15,5 km;
  • Lot 3.3, between Kresna and Sandanski, which is 23,6 km long.


Activities for the preparation of Lot 3

The following preparation activities for the completion of the project have been identified::

  • Preparation of preliminary design for Struma Motorway, Lot 3 “Blagoevgrad - Sandanski”;
  • Consultancy service from a strategic advisor for the construction of Struma Motorway, Lot 3 “Blagoevgrad – Sandanski”;
  • Consultancy services from environmental specialist for the construction of Struma Motorway, Lot 3 “Blagoevgrad – Sandanski”;
  • Geological studies for the preparation of Struma Motorway, Lot 3 “Blagoevgrad – Sandanski” for the tunnel sections in the Kresna Gorge and Zheleznitsa;
  • Preliminary archeological studies for Struma Motorway, Lot 3 “Blagoevgrad – Sandanski”;
  • Monitoring, analysis and assessment of animal mortality in section E-79 (I-1), pаssing though the protected areas “Kresna” and “Kresna – Ilindentsi” for the periods of 2013 – 2014 and 2014 – 2015;
  • Traffic monitoring at road E-79 (I-1), pаssing though the protected areas “Kresna” and “Kresna – Ilindentsi”;
  • Road safety audit of the preliminary design of Struma Motorway, Road part and Tunnels part;
  • Traffic forecast update and “cost – benefit” analysis update for Lot 3 of the Struma Motorway;
  • Preparation of equivalent monetary compensation statement and technical mediation for the implementation of the procedure for a land acquisition for the completion of Struma Motorway, Lot 3;
  • Preliminary design for the section of Lot 3.2 of Struma Motorway in the Kresna Gorge;
  • Preparation of EIA and AA report for improvement of the alignment of Lot 3.2 of Struma Motorway.


Construction activities

The completion of Lot 3 will be carried out under four construction contracts with the corresponding supervision contracts:

  • Lot 3.1 from Blagoevgrad to Krupnik (from km 359+000 to km 376+000);
  • Tunnel north of Zheleznitsa with length of approximately 2 km;
  • Lot 3.2 between Krupnik and Kresna (from km 376+000 to km 397+000);
  • Lot 3.3 from Kresna to Sandanski (from km 397+000 to km 420+628).

On 25.09.2015 the contract agreements for construction and for supervision of Lot 3.3 were signed.

On 30.12.2015 the contract agreements for construction and for supervision of Lot 3.1 were signed.




There have been numerous design studies on the Struma Motorway during the past years.

The development of the project began in 1990 with a feasibility study by the Bulgarian design bureau Patproject. The study focused mostly on the technical feasibility of the alternatives and did not include an in-depth economic or environmental appraisal.

Ten years later, between 2000-2002, the Italian company SPEA Ingegneria Europea was commissioned to prepare feasibility studies, preliminary EIA, design and tender documents for the Struma Motorway. SPEA produced many alignment alternatives (to a large extent based on the work by Patproject), plus alternatives of the alignment avoiding the Kresna Gorge. The study included traffic forecasts, cost estimates, cost-benefit analysis, multi-criteria analysis, preliminary EIA, etc. SPEA did not study the same detailed analysis on all sections.

Parallel with the work of SPEA, the Bulgarian design company Krasi-Bo prepared and justified an additional alternative for the whole motorway section. This route attempted to reduce the capital cost projections and to avoid specific problems in some sections, such as conflicts with the master plans of some municipalities. Vertical alignments and typical cross-section drawings were produced for two alternatives proposed within the study – brown and brown-dotted. These alignments were compared against the respective combinations of SPEA alternatives by defined indicators. As a conclusion the study proposed a combination of the brown and brown-dotted alternatives as a preferred solution.

The outcomes of the SPEA and Krasi-Bo studies were reviewed by the Supreme Technical Expert Council of the country in 2002. They considered all proposed technically feasible alternatives and variants, and approved a mixture of them for further analysis and development.

In 2007, the Bulgarian design company NSI-2000 was commissioned to carry out a number of studies related to the Struma Motorway. The first of these related to the section in the Kresna Gorge and resulted in two new long tunnel alternatives. They also developed additional alternatives for the gorge and two new alternatives near the village of Bialo Pole.

Based on the outcome of the EIA and the Appropriate Assessment Studies from 2007, the EIA Decision No. 1-1/2008 approved a preferred alignment for the entire length of the Struma motorway, as a combination of several previously studied alignments, but predominantly based on the brown alternative developed by Krasi-Bo. This Decision also provided numerous recommendations for further improvement of the alignment during the next stages.

The approved alignment was further amended in the section between Byalo Pole and Blagoevgrad in 2009 by virtue of Decision No.16-ПР/2009 in line with the recommendations of the original EIA decision. The alignment in this section was further amended by Decision No. 28-ПР/2009.

EIA Decision No. 5-3/2010 of 2010 amended a short section of the vertical alignment near the Marikostinovo village (in the scope of Lot 4) where in 2011 Decision No. 25-ПР/2011 was issued.

Due to the long time span of the feasibility studies process and its fragmentation over time, Arup were commissioned by JASPERS in 2011 to produce an update and review of the work to date. This was to review the process which identified preferred (approved) alignments for the Struma Motorway Lots 1 to 4, to review whether the process was concluded satisfactorily, and to confirm the preferred alignments through a Multi Criteria Analysis. The conclusion was that the preferred (EIA approved) alignments for all Lots could be confirmed as the optimal solution. In the process a cost estimation, traffic estimation, as well as a report dealing with the potential for construction of a long tunnel in Kresna Gorge have been developed.

In late 2011/early 2012, RIA has commissioned surveys and further preliminary design work as follows:

  • Alignment (by NSI-2000) - revisions to the horizontal alignment were made to affect key issues concerning the main problems. The output includes 1:25000 scale plans to aerial photo base, and 1:10000/1000 plan/profiles covering all of Lot 3. The new route deviates from previously approved routes with up to 1 km, over lengths of approximately 30 km in total. The tunnel route has not accounted for geological survey findings 
  • Topographical Survey (by TransGeo) - the output from this survey included 1:2000 scale plans covering all of Lot 3, based on the EIA approved alignment. It mostly covers a measurement of 200 m, as compared to the levelling, and widens at specific locations for interchanges etc, and over the proposed tunnel section.  
  • Geological Survey (by Geotechnica Engineering Ltd) - this survey was of limited extent within the scope of Lot 3.2. and was targeted at the potential for intermediate construction accesses along the tunnel route and at the tunnel portals. Significant issues were raised, including fault zones, slope instability, ground water, seismicity etc.  

In 2011 a road safety audit was commissioned by EIB and carried out for Lots 1 and 4 where detailed designs were available. Road safety guidelines for design of Lots 2 and 3 were also delivered.


Project Financing

The project “Struma Motorway, Lot 1, 2 and 4”, which also includes the preparation of Lot 3 is financed by Operational Programme on Transport 2007-2013.

On 10 June 2013, a contract for grant assistance was signed under Project № 161PO004-2.0.01-0019 for the preparation of Lot 3 as part of the project “Struma Motorway, Lot 1, 2 and 4”. The provided financing is to the amount of BGN 7 776 928. The project is financed through Operational Programme on Transport 2007-2013 by means of the Cohesion fund.

The construction of Lot 3 of Struma Motorway will be financed as a priority project under Operational Programme on Transport and Transport Infrastructure 2014 – 2020.

On 24.09.2015 a grant contract № ДОПТТИ-1/24.09.2015 was signed and National Company Strategic Infrastructure Projects was provided with grant for the implementation of project № BG16M1OP001-2.001-0001 „Struma Motorway Lot 3.1, 3.3 and Tunnel Zheleznitsa“. The project will be developed under Priority Axis 2 „Development of road infrastructure along the „core“ and „comprehensive“ Trans-European Transport Network“ of the Operational Programme „Transport and Transport Infrastructure“ 2014-2020 and will be financed by the Cohesion Fund. The total value of the financing under the grant contract is BGN 739 245 318,00, where BGN 628 358 520,30 will be provided through the Cohesion Fund of the European Union and BGN 110 886 797,70 is the amount of the national co-financing.