This road that you are travelling on is actually the oldest road in Yishun and Sembawang! Built sometime in the early 1850s, it used to be known as Seletar Road, before the lower stretch was renamed Thomson Road after the Government Surveyor, John Turnbull Thomson (1821-1884).
In 1939, it was officially announced that the stretch of road from the junction of Mandai Road and Seletar Road all the way up to the north would be renamed Sembawang Road. Apparently, the name ‘Seletar Road’ had caused confusion as the area where the former Singapore Naval Base and the British airbases were also referred to loosely as ‘Seletar’.
It is unclear what the origins of the name ‘Sembawang’ are. In a map dated 1830, the river now known as Sungei Sembawang was labelled as River Tambuwang. Some sources have suggested that the name ‘Sembawang’ probably came from the name of a riverine plant, the Sembawang tree. (mesua ferruginea). This tree can be found in Carpark C1 in Sembawang Park.
Right up to the 1980s, this road was the only one linking this part of Singapore to town. In the 1800s and early 1900s, most residents staying here had to travel by boats down Seletar River and other waterways to town instead!