The 18.3 km high-speed road will include bridges with a total length of 2.5 km, the infrastructure ministry said in a statement on Wednesday.
"We will arrive in Belgrade from Valjevo in less than an hour, new investors will come to Valjevo and there will be new jobs," President Aleksandar Vucic said during the official start of the construction works.
During the construction works, the flow of Kolubara river will be regulated to prevent further floodings, the ministry said in the statement.
Serbia's government signed a 158 million euro agreement for the construction of the high-speed road with SDHS last week.
In August 2019 Serbia opened for traffic the 62.7 km motorway section between Obrenovac and Ljig, thus completing the Obrenovac-Cacak section of Milos Veliki.
($ = 0.8893 euro)