Jerusalem has advanced construction activity on its 31km Blue Line light rail corridor, issuing municipal notices in early December confirming the continuation of utility and surface infrastructure work along King George Street, the most restricted segment of the alignment and the planned site of a 2km tunnel extension under the central business district.
The municipality said in a December construction notice posted on its official website, a Hebrew-language newsletter that is region-restricted to users outside of Israel, that “the Municipality of Jerusalem and the Eden Company have begun infrastructure works on King George Street as part of the Blue Line project,” confirming that enabling works are active along one of the city’s busiest commercial corridors.
The notice describes the phased road adjustments and service changes required to clear the route for the installation of the guideway and the future staging of the underground works.
The Blue Line is being delivered as a public-private partnership under a 2023 concession awarded to a consortium of Israeli companies Danya Cebus and Dan Transportation, and Spain-based contractor COMSA, it said. The Jerusalem Post.
Municipal planning documents reviewed by ENR describe the line as “[connecting] the neighborhood of Ramot in the north with Gilo in the south, passing through the center of the city.” The association covers about 31 km through the Blue axis and its Azure and Purple connecting lines, with the main trunk from Gilo to Ramot measuring approximately 20 km.
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Jerusalem’s city center encompasses the Mahane Yehuda market district, one of its main commercial hubs, and the axis of Jaffa Street before the alignment continues south to Gilo along the main approach arteries. Government and financial industry documents continue to cite an estimated cost of around $2.8 billion for the partnership project. Officials have not released a revised figure that reflects current market conditions.
Drive engineering of the tunnel section
.jpg "Map of the blue line")
The map of Jerusalem’s planned Blue Line shows the 31 km alignment running from Ramot in the north through the city center to Gilo in the south, including the restricted segment of the city center where a 2 km tunnel is planned under King George Street and adjacent commercial corridors.
Image courtesy of openstreetmap.org
The central section presents the most demanding civil works conditions of the project. The alignment is to pass under King George Street, the Ben Yehuda Pedestrian Zone and the Red Line Jaffa Street Corridor – areas with narrow rights-of-way, high pedestrian volumes and existing traffic operations.
Local reports on city project materials note that “the plan calls for building a 2 km underground tunnel under the city center, including several subway stations,” to preserve surface mobility and avoid conflicts with Red Line rail service. GeoConsult’s technical documents describing the “Blue Line Metro Section” support the 2 km length and multiple metro stations.
SYSTRA prepared the preliminary design of the line in collaboration with local partners, establishing the basic concepts of alignment and station. GeoConsult reports on the completion of underground and geotechnical studies for the midtown segment.
The municipality has not released documentation on the tunneling method, construction sequencing or contract-level disclosures identifying the companies that will execute the excavation and construction of the station box. Officials have not yet provided an expected start date for tunneling activities.
Geology adds complexity
Geological cross-section of the Judean Mountains shows the alternating formations of Cretaceous limestone, dolomite, chalk, and marl that underlie central Jerusalem. These layered units, many of which contain karst voids, fractured beds, and exposed groundwater, create variable ground conditions that influence tunnel alignment, support requirements, and station box depth along the 2 km underground segment of the Blue Line.
Image courtesy of ARJ
Jerusalem lies atop Cretaceous limestone and dolomite rock formations of the Judea Group, with intercalated chalk and marls that vary in strength and fracture behavior, according to the Israel Geological Survey and regional engineering and geology studies.
These strata may contain karst voids, jointed blocks, and exposed groundwater, conditions that make deep excavation difficult and may require specialized support systems.
The city’s ridge and valley topography concentrates development along narrow spines, leaving steep slopes and limited overburden in the center.
Dense archaeological deposits layered below the surface add further constraints. Together, these factors help explain the engineers’ decision to route the narrowest segment of the Blue Line underground instead of widening or upgrading the surface corridors.
Suburban stops such as Ramot in the north sit on elongated ridges with elevations of approximately 693 and 850 m, reflecting the hilly, ridge and valley terrain on which the sprawling suburbs are built.
Design criteria, next steps
The Design Criteria for the Jerusalem Light Rail System sets out the geometric, structural and systems parameters that govern the tunnel. The design criteria allow mainline gradients of up to 7% on the flatline (increasing to 9% in exceptional cases) and allow horizontal curve radii as narrow as 25m on very restricted segments. Local elevation changes and limited rights-of-way shape these parameters.
The criteria also define the structural envelope of the tunnel, including the clearance for vehicle swing, the 750 V DC overhead contact system and the space required for the emergency walkway, all of which determine the tunnel diameter and station box geometry.
Noise and vibration thresholds may require resilient pathways through sections of the commercial backbone to protect sensitive buildings and historic structures.
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Municipal materials emphasize that a tunnel is necessary because the central corridors cannot simultaneously support a level guide, heavy pedestrian flows and dense networks of public services. Following construction, portions of King George Street are expected to transition to a pedestrian-focused, traffic-priority use.
Officials continue to refer to a phased rollout, with the segment between the Gilo stop and downtown expected to begin service later this decade with full Blue Line operations planned for 2030, according to association filings that describe a phased activation beginning in 2028.
More bulletins are expected as utility relocation, excavation preparation and station area preparation continue along the tunnel area approaches.
