Gebze–Izmit Motorway Rehabilitation

Superstructure Rehabilitation and Completion of Structures on the Gebze–Izmit Section (Km: 45+300 – 82+600) of the Anatolian Motorway and its Link Roads.

This project aimed to rehabilitate the deteriorated superstructure of the Gebze–Izmit section of the motorway. The asphalt thickness was increased from 19 cm to 25 cm to enhance load-bearing capacity and meet increasing traffic demands. Additionally, the existing emergency lanes were converted into active lanes, expanding the road into a 2x3 lane configuration and creating emergency parking bays.

Another key component was the expansion of the 11 km-long single carriageway between the Tüpraş Junction and İzmit West Provincial Junction into a 2x3 lane road to better accommodate rising traffic volumes. The total length of the upgraded road is 103 km.

Client: General Directorate of Highways, 1st Regional Directorate

Location: Istanbul, Türkiye

Construction Period: 1995 – 2005

Topçular Bridge Interchange

Located within the Gebze district of Kocaeli Province, the D-100 Topçular Interchange is situated on the D-100 State Highway. The project consists of 1,400 meters of main road passage and 3,750 meters of side roads and connection roads.

The project features a 2x3 lane traffic flow on the main carriageway and includes a 15-span bridge, 2x14 intermediate piers, and a total bridge length of 325 meters.

In addition to the vehicular lanes, the structure includes pedestrian walkways measuring 2x(1.5 + 1.0) meters. The total platform width is 2x16 meters = 32 meters.

Upon completion, D-100 highway traffic was redirected via the elevated interchange, while traffic from Darıca–Gebze Road, the north and south side roads, and connection roads is managed through an at-grade intersection beneath the bridge.

Client: Gebze Municipality

Location: Kocaeli / Türkiye

Construction Period: 2014-2015

Haydarpaşa – İzmit Motorway and Interchanges Project

This project involved the renovation and expansion of superstructure and civil structures located at the Bostancı, Maltepe, Dilderesi, and Hereke interchanges along the Haydarpaşa–İzmit Motorway.

Client: General Directorate of Highways, 1st Regional Directorate

Location: Istanbul, Türkiye

Construction Period: 1986 – 1992

D-100 Istanbul–Gebze–Izmit Road: Construction of Çayırova, Hanibal, Gebze East, Dilovası, and Eynerce Interchanges

Completion of Earthworks, Structures, Bridges, Superstructure, and Miscellaneous Works on the D-100 Istanbul–Gebze–Izmit State Road. (including Çayırova, Hanibal, Gebze East, Dilovası, and Eynerce Interchanges)

This project, implemented along the Gebze–Izmit section of the D-100 dual carriageway between Istanbul and Kocaeli, aimed to relieve heavy traffic by eliminating at-grade junctions and streamlining the corridor through new grade-separated interchanges and infrastructure upgrades. A total of five interchanges were constructed, incorporating both flyovers and deep pile-supported underpasses (commonly known as "cut-and-cover" or "split-level" interchanges). In addition to the interchange works, pavement improvements were carried out along a 38 km stretch of the route. The existing asphalt surface was milled where necessary and replaced with a high-performance stone mastic asphalt (SMA) layer. All construction activities were carried out under live traffic conditions with careful phasing and traffic management.

Client: General Directorate of Highways, 1st Regional Directorate

Location: Gebze, Kocaeli / Türkiye

Construction Period: 2015 – 2020

Gebze–Izmit Highway: Şirinyalı–Tavşancıl Interchange Section

Construction Works for Superstructure, Bridges, and Related Structures on the D-100 State Road between km: 59+450 and km: 69+300 (Şirinyalı–Tavşancıl Section)

As part of this project, the existing 10 km-long 2-lane (1 lane per direction) road was upgraded to a 4-lane (2 lanes per direction) divided highway. In addition to the superstructure works, five grade-separated interchanges were constructed. Due to the narrow corridor in the Hereke section—situated between the elevated TEM Motorway and the lower TCDD Ankara–Istanbul main railway line—the standard dual carriageway cross-section could not be applied. Therefore, for the first time in Türkiye, a 7.50-meter-wide cantilevered road design was implemented.

Client: General Directorate of Highways, 1st Regional Directorate

Location: İzmit / Türkiye

Construction Period: 2006 – 2010

Gebze-İzmit TCDD Railway Construction Project

Relocation of the TCDD Railway Section between Km: 65+830 – 67+244 to a Variant Alignment on the D-100 State Road Gebze–Izmit Section.

As part of the realignment of the TCDD railway line, the project included 250,000 m³ of earthworks, 35,000 m³ of structural concrete for engineering structures, the installation of prestressed precast sleepers, and the execution of electromechanical systems.

Client: General Directorate of Highways 17th Regional Directorate

Location: Izmit, Türkiye

Construction Period: 2009-2010

Büyükçekmece – Küçükçekmece Viaducts

Construction of Küçükçekmece I and Büyükçekmece I Bridges with Precast Beams and Renovation of Küçükçekmece II Bridge.

This project was undertaken to reduce traffic congestion in the Büyükçekmece and Küçükçekmece districts. It involved the construction of the 6-span Büyükçekmece Bridge and the renovation of the 4-span Küçükçekmece Bridge.

Client: General Directorate of Highways – 1st Regional Directorate

Location: Istanbul, Türkiye

Construction Period: 1993 – 1996

Sakarya Interchange – Gümüşova Road Construction Project

Superstructure Improvement Works on the Motorway and Connection Roads between Sakarya Interchange and Gümüşova.

This project involved the rehabilitation and maintenance of a total of 52 km of existing 2x3 lane motorway and its connection roads. The scope of work included:

• Milling of the existing superstructure,
• Application of bituminous binder layers containing 10% recycled material,
• Placement of a 4 cm stone mastic asphalt (SMA) wearing course over sub-base and base layers reinforced with geogrid.

Client: General Directorate of Highways, 17th Regional Directorate

Location: Izmit, Türkiye

Construction Period: 2006 – 2010

Samandıra – Kartal Intersections Project

Construction of Connection and Side Roads between Samandıra Interchange on the Motorway and E-5 Kartal Interchange.

This project involved the construction of interchange structures providing connectivity between Samandıra Road and the E-5 corridor in Istanbul’s Kartal district. The scope included superstructure and substructure works, major and minor engineering structures, traffic signage, lighting and electrification systems, and landscaping.

Client: General Directorate of Highways – 1st Regional Directorate

Location: Istanbul, Türkiye

Construction Period: 1990 – 1996

Pendik-Kurtköy Interchange

Construction of the E-5 Bridge Interchange on the Pendik–Kurtköy Road.

This project involves the construction of a grade-separated interchange, bridge, and underpass on the D-100 Highway at Pendik–Kurtköy. The scope includes all infrastructure and superstructure works, culverts, structural components, and the implementation of traffic signage and road marking systems.

Client: Istanbul Metropolitan City Municipality Department of Infrastructure Coordination

Location: Istanbul, Türkiye

Construction Period: 1997-2000

Mahmutbey-Airport Connection Road Construction

Construction of Infrastructure, Grade-Separated Junctions, and Side Roads for the European Motorway Section 2: Mahmutbey–Airport Connection.

Located in Istanbul, this project involved the complete construction of infrastructure, engineering structures, interchanges, and service roads for the connection route. The motorway was built with a total length of 20 km and a 2x2 lane configuration.

Client: General Directorate of Highways

Location: Istanbul, Türkiye

Construction Period: 1983-1987

Gebze - Sile State Highway

This project covers the construction of the motorway section between TEM Çayırova Interchange and Şile, including roadworks, engineering structures, asphalt paving, and superstructure works. The scope includes all earthworks, superstructure applications, major and minor engineering structures, traffic signage, and landscaping works.

The road is designed as a 2x2 lane dual carriageway with a total length of 28 kilometers.

Client: General Directorate of Highways 1st Regional Directorate

Location: Izmit, Türkiye

Construction Period: 1995-2001