The A1 is closed at Grantham after a serious accident which happened just before 8am today (Friday) on the carriageway by the bridge on Dysart Road.
The bridge itself has now been closed and cordoned off by police.
A section of the A1 between the A52 and the A607 junctions has also been closed and diversions are being put in place.
The closures are expected to go on for several hours as investgations take place. A police spokesman said the force cannot release further details at this time.
More details when we have them.