Buses in London are now using a radio system designed in Christchurch, New Zealand.
Tait Radio Communications has finished the installation of a new network radio communications system, on 7500 buses.
The $19 million contract is one of the company's largest deals yet.
London's buses carry six million passengers per day.
Chief marketing officer James Kidd says regular communication between dispatchers and bus drivers on traffic jams road closures or emergencies are critical for efficient running.