BENGALURU: The state cabinet on Thursday granted administrative approval for construction of an 18.5-km tunnel road from Hebbal to Central Silk Board Junction on Hosur Road at an estimated cost of Rs 12,690 crore. The cabinet also approved a 250-foot tall skydeck project in Bengaluru to be built at a cost of Rs 500 crore. Initially, 11 high-density corridors were …