The decision to upgrade routes near the new Forth road bridge by the Scotland Transport Agency is likely to disrupt traffic for nearly three-and-a-half years.

Commuters in the east of Scotland may face prolonged delays during construction of a new junction at this site, according to

Nearly 70,000 vehicles pass the junction, which is adjacent to a to a 1,000-space park-and-ride bus interchange.

Interim project director John Howison said contraflows may be in operation during the construction period for the new junction and upgrading of the A90 road at this location.

“Two lanes will be kept open in each direction on the A90 road during the day,” Howison said.

The upgrade work is expected to cost one-third of the project’s £2bn ($3bn) budget, and is scheduled to open in late 2016.