Metro Tunnel
The Metro Tunnel (sometimes also known as the Melbourne Metro Rail Project or the Metro Rail Capacity Project) is a metropolitan rail infrastructure project currently under construction in Melbourne, Australia. It includes the construction of twin 9-kilometre rail tunnels between South Kensington station (north west of the Melbourne City Centre) and South Yarra (in the south east) with five new underground stations. The southern portal for the tunnel is to be located to the south of South Yarra station. As a result, the tunnel will connect the Pakenham and Cranbourne lines with the Sunbury line, and allow these lines to bypass Flinders Street station and the City Loop while still stopping in the Melbourne central business district.
Savamala
Pushing their pet project, Belgrade Watefront, the city government announced in May 2017 that it has decided on the future route of the tunnel. From the direction of Savamala, it will enter underground apparently at the same place as planned before, near the Park Luka Ćelović and the University of Belgrade Faculty of Economics and will come out at the Stefan "Bulevar Despota Stefana", near the building of the Belgrade City Police, with the total length of . It will pass beneath Terazije (where it will reach its lowest, below ground) and Nikola Pašić Square. The tunnel will have two separate tubes for each direction. Each tube will be wide, with two wide lanes, two pedestrian pathways of and two evacuation exits for the vehicles. At the entry and exit points, 21 objects would have to be demolished, with the total area of . Also, the Palilula exit section, streets of "Cvijićeva" and "Dunavska", would have to be widened and adapted for the future traffic coming out of the tunnel. Analysis showed that the ground traffic will be relieved of 3,120 vehicles per hour, which will result in the reduction of the vehicle number in downtown by 10–15%, and driving time and carbon-dioxide emission by 10%. At Savamala entry point, there will be constructed a roundabout in "Karađorđeva" street to accommodate both the tunnel and the future new bridge on the Sava, after the surprising decision by the city authorities to demolish the Old Sava Bridge and build a new one. It is expected for the construction of the tunnel to begin in late 2018 and to be finished in 30 months, i.e., by the mid-2021. Original estimates placed the price of the project between 100 and 130 million euros, but the city government now claims that it will cost only 78 millions. Still, it is more of a conceptual design for now, as the full plans and projects are yet to be done.