The Department for Transport (DfT) has admitted an error in describing the A428 in Cambridgeshire as England's least reliable road.
The road takes drivers between the A1 and the M11 near Cambridge.
The best performing stretch managed by the Highways Agency, was said to be a stretch of the M4.
But the DfT has now revealed some of the congestion statistics for the A428 were faulty leading them to withdraw the data "for all individual routes".
A spokesman said: "We are urgently reviewing our data checking procedures to establish why this error was not identified earlier and ensure this does not happen again."
The revised data will be revealed "as soon as possible", said the DfT.