Minister of Public Works and Public Housing (PUPR) Basuki Hadimuljono's project has 550 Meters long tunnel will have two tubes one leading to Jogja and one to Semarang. The depth is 50 meters from the surface.

Study still continue for whether tunnel construction worth the investment.

https://borobudurnews.com/unik-bakal-ada-terowongan-550-meter-di-tol-yogyakarta-bawen/