Drivers travelling at speeds of more than 100mph, including one at 146 mph, were stopped by police during checks on the A47 at Terrington St John.
Patrols on the stretch last Saturday saw six drivers reported for travelling at more than 100mph in a short period of time.
Drivers clocked 103, 105, 114, 127 and 146mph.
Officers from Norfolk and Suffolk Roads Policing Team tweeted the speeds on social media and said: “unbelievable”.
One of the drivers travelling at 103mph was arrested on suspicion of drug-driving.
Officers have reminded drivers that speeding is one of the Fatal 4 behaviours which can contribute to causing serious road crashes and even death.
Fatal 4 is part of a hard-hitting national campaign which also highlights the dangers of driving under the influence of drink or drugs.