The technology is being trialled by TfL along with the Metropolitan Police as part of the Vision Zero strategy,, external which aims make London’s roads safer.
TfL said there was no fixed period for the trial and it would continually assess the results.
Siwan Hayward, TfL’s director of security, policing and enforcement, said: “Upgrading our camera network is vital to maintaining strong, consistent enforcement, and together with the Met we are using every tool available to deter speeding, reduce road danger and save lives.”
IAM said the new technology was an “opportunity to change behaviour” as there had been poor compliance with 20 mph speed limits in London.
“It is, however, worth noting that average speeds in London are below 20 mph, so we would also like to see enforcement focus on things like drivers illegally using mobile phones at the wheel alongside these new trials,” a spokesperson added.