The black cab cab is an iconic symbol of all things British and with the help from an ambitious trial by the RSA, they could be turning green.

A handful of our fair capital’s “cabbies” are set to have “spring-o-meters” dash board mounted devices that give the driver an audible warning when they brake or  accelerate too sharply. By encouraging hypermiling & smooth driving the The Royal Society for the Encouragement is hoping to cut the equivalent of 200kg of carbon emissions while saving cabbies a whopping £600 in fuel bills.

Passengers will also be able to comment on their journey, guest books will be provided so feedback on their drivers “hypermiling” can be gathered.

In association with the Shell Smarter Cab Drivers month long challenge, 20 cab drivers will be able to competing online to see who can be crowned the UK’s most green cabbie. Using both in car telemetry devices and manual recording they will see who is using the Shell Smarter Driving Top tips to the maximum benefit.

Search for “smarter cab drivers” in google to find out more or check out the RSA’s website.