Motorists can expect traffic snarls along some roads where the Thomson MRT Line is being built, transport experts say.
They expect the roads around the Upper Thomson, Stevens and Orchard stations to be most affected by the construction.
The 30km, $18 billion line will start in Woodlands and traverse heavily used roads such as Upper Thomson Road and Stevens Road.
It will have 22 stations, six of which are interchange stations, and open in three phases from 2019 to 2021.
The Land Transport Authority (LTA) said it will call civil tenders for the project as early as next month.
Its spokesman said the authority will assess the impact of the works on traffic flow.
To maintain the capacity of affected roads, new traffic lanes will be provided to replace those removed in the course of the construction, she said.
The LTA will also inform the public about traffic diversions in advance and through its OneMotoring website.