Thomson Road is a major trunk road linking Singapore's central business district with the northern suburban areas. Taking its name from John Turnbull Thomson, a Scotsman who was the Government Surveyor and Chief Engineer of the Straits Settlements from 1841 to 1853 and who helped build many roads into the interior of the island beyond the core of the city centre in the south.
Originally known as Seletar Road (the later of which is now the name of a small road off Yio Chu Kang Road in Seletar Hills Estate), it was known to the Chinese as Chia Chui Kang, literally meaning "freshwater stream" in reference to the Kallang River which crosses the road in its upper reaches near the traditional core area of present day Ang Mo Kio. Thus, it was also known as Ang Kio Tau, meaning "head of the red bridge", the same bridge which may have given Ang Mo Kio its name. It also had a Tamil name, Thanir Pilei Sadakku, literally meaning "water-pipe street".
Today, the road begins at a major road junction with Keng Lee Road, Kampong Java Road, Cavenagh Road and Norfolk Road, and leads northwards through the Novena residential area. It passes by Toa Payoh before continuing on as Upper Thomson Road at the junction with Braddell Road and Lornie Road. It skims along the western edge of Bishan and Ang Mo Kio, then cuts through relatively undeveloped areas until it reaches the junction with Mandai Road, where it continues northwards via Sembawang Road. It is also the site of St. Joseph Institution International, Ministry of Youth and many more. This road also is affected with the North - South Corridor construction.