Motorists nearly 20mph over the speed limit were caught by police carrying out speed checks in Soham, Littlport and Ely.
Speeds of 42 and 49mph were recorded by officers in Ely Road, Littleport, and Witchford Road in Ely.
Multiple tickets were issued and other drivers given words of advice.
A post on Policing East Cambridgeshire read: "Slow down, it's 30 for a reason #SaferCambs."
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