Deputy Mayor Goran Vesić has announced that the contract with Egis would be signed this week.

The construction of the first subway line for Belgrade will finish in 2028. This mentioned contract is only for design and only for the second line which will be finished in 2030. The second line will have 16 stations and their design will be subject to an architectural competition being prepared together with the Association of Architects of Belgrade.

According to Politika,  Vesić said "We are finishing geological research. ...the probes are going down to a depth of 60 meters, because based on those results, the Chinese are projecting a 'mole' that will dig a tunnel that will be 10 meters wide ".

https://www.politika.rs/scc/clanak/484249/Do-kraja-nedelje-ugovor-za-projektovanje-druge-linije-metroa