It’s not a symbol on US-spec cars. Does your Prius have ITS installed? Did an emergency vehicle drive by when you saw that symbol? We’re you at an intersection when you saw that sign?
No. And I cant find the pattern when this sign is appearing at all. Sometimes it appears when the car is stop, sometimes when the car is moving. And also day and night
As mentioned, there's no symbol. like that in the North American cars so it won't be in our owners manuals.
As @Tideland Prius kindly suggested, the green symbol on the main display is related to the ITS Connect feature offered by Toyota on vehicles built for sale in Japan. It indicates that vehicle-to-vehicle (V2V) communication has been established with another nearby vehicle having similar equipment. See ARIB STD-T109 and ITS Forum RC-013 (PDF) for details. The symbol is explained briefly on Toyota’s ITS Connect page (in Japanese). The communication-based radar cruise control and ITS Connect features are described further in Japanese editions of the Owner’s Manual (PDF, in Japanese); see pages 271–289 of the edition linked here. One important point, mentioned on page 287: if you’re not in Japan, the 760 MHz radio transmitter in the car used for this feature may violate local laws and regulations, and you may wish to have it removed or disabled.
So the tractor beam theory wasn't that far off !! We can just change it to communication beam activated ....
