Two stretches of Upper Aljunied Road will be closed permanently and a larger realigned road will take their place from tomorrow, a Housing Board statement said.
These changes will allow the construction of a 700m pedestrianised Bidadari Heritage Walk for the upcoming estate.
The junction at Upper Serangoon and Upper Aljunied roads will also be removed.
There will be a new dedicated U-turn underneath the Upper Serangoon Road viaduct.
Barricades and diversion signs will guide motorists.
The new road will continue to allow access to Vernon Park Road where the Gurkha Contingent is based, Mount Vernon Columbarium and privately-run funeral parlours in the area.
The columbarium will soon be demolished to make way for the new estate and the niches claimed by June 30 will be relocated to Mandai Columbarium.
Unclaimed niches will face removal.
The tree-lined heritage trail, featuring the estate's rich history, will link the future Alkaff Lake with the Bidadari Park to the north.
"This will create a contiguous and conducive parkland within Bidadari for residents to walk and cycle safely around the estate," HDB said.
Bidadari Greenway, a 20m-wide green space lined with rest spots as well as commercial and communal facilities, will cut across the estate.
The HDB has launched 4,800 flats in Bidadari since November 2015, with another 1,340 due to be offered in May.
A site for private residential developments was put up for tender on Monday.
It is expected to provide another 825 homes.