Aberdeen Tunnel [1982- ]

It was completed in 1982:

 A north-south route, the section of Route 1 through
the centre of the Island, comprising the Aberdeen Tunnel
and grade-separated road networks at its approaches,
was completed in March 1982, linking Aberdeen with
Happy Valley and the Cross Harbour Tunnel. 

http://www.gov.hk/en/about/abouthk/factsheets/docs/highways.pdf

It was built by Dragages:

Challeneged by a combination of hard rock and poor soil conditions, heavy arch ribbing and hand-excavation were used for precarious sections of the tunnel. The remainder was excavated using hydraulic and pneumatic jumbos.

http://www.dragageshk.com/pdf/FactSheet-Tunnel.pdf

Additional info from the CEDD:

• Project Title: Route 1 – Aberdeen Tunnel (dual 2-lane)
• Year of Completion: 1982
• Length Details: 1.9 km (twin tubes)
• Cross Section Details: 10.0 m span x 11.0 m high horseshoe shaped 
• Method of Construction: Drill & blast (pilot tunnel constructed) , lining 0.61 m thick min.
• Geology and Groundwater: 1.55 km weathered to fresh granite; 250 m volcanic rock including 50 m weathered quartz monzonite; groundwater problems near the ground surface at portal area 
• References: Chappell & Tonge (1975; 1976), Twist & Tonge (1979), Cochrane (1984)

https://www.cedd.gov.hk/filemanager/eng/content_446/Catalogue%20of%20HK%...