Police are using unmarked cars for their patrols
Devon and Cornwall Police say they are so shocked by results of an operation to catch dangerous and speeding drivers that they are going to repeat it.
About 1,000 motorists were stopped by the police as part of Operation Vortex in March, with 831 having action taken against them for motoring offences.
Some 379 motorists were caught driving faster than 90mph (145km/h) and one was caught driving at 130mph (209km/h).
Nearly 600 fixed penalty tickets were issued, plus many court summonses.
Of those stopped, 413 were found to be speeding, 162 were driving using a hand-held mobile phone and 167 were not wearing seat belts.
Insp Richard Pryce, of the force's roads policing unit, said: "It is very disappointing that so many motorists consider themselves above the law and consciously flout basic elements of road safety.
He added that officers had been "astounded" at the actions of some motorists who "deliberately take completely unnecessary risks, displaying no regard for road safety".
Police said they would continue to repeat the operation across both counties and that careless or arrogant driving would not be tolerated.
The operation involves the use of a fleet of unmarked cars to patrol main routes in both counties.