Drivers are facing a 21-mile diversion route while an emergency road closure is in place.
The B1115 in Little Waldingfield near Sudbury will be closed from 10am until 3pm on Thursday.
According to the Suffolk County Council website the official diversion route is 21 miles.
While the road is closed Suffolk County Council will be carrying out "urgent carriageway patching" according to the council's website.
The diversion is expected to add on around 40 minutes to people's journeys.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here