They are part of a plan by the Highways Agency to create “smart” motorways that aim to keep traffic flowing smoothly.
Other measures include pressing the hard shoulder into service as an additional peak hours lane.
Motoring organisations claim the new cameras will lead to thousands of motorists being stung with fines of at least £100 and getting points on their licence for only marginally breaking the speed limit.
Kent police figures for the new cameras installed between junctions five and six show 520 drivers were penalised for breaking the 70mph limit.
A further 148 tickets were issued those for breaking variable speed limits of between 40mph and 60mph.
A Highways Agency spokesman said: “There are clear signs where cameras are in place and the new cameras are more visible than the previous versions.”
