The system that enables you to listen to your car radio when driving through tunnels in Hong Kong also allows the tunnel companies to override the radio signal with their own transmissions. This is fine when they use it to make helpful traffic announcements, such as telling you that a particular exit road is closed or when a blockage will be cleared. And indeed they sometimes do this (though as my wife noted, only in Cantonese - perhaps English or Putonghua speakers don't drive?).
Unfortunately they don't limit themselves to this. It is intensely irritating to be listening to the RTHK news in the Lion Rock Tunnel, only to have the airwaves hijacked by some inane do-gooder relaying unnecessary government propaganda, like telling you not to drink and drive. Almost as irritating, in fact, as watching television and having the government exhort you to "love your family" (seriously) during the commercial breaks. Where do these people think we are - Singapore?