A method and a radio beacon for transmitting messages between a radio beacon and multiple onboard units passing this with unique identifiers in a road toll system, wherein the messages respectively provided with an identifier of an onboard unit are stored in a buffer memory of the radio beacon for sequential processing or despatch. The method including determining, of each onboard unit entering the transmitting-receiving area of the radio beacon, at least one characteristic of the onboard unit, sorting the messages present in the buffer memory under the identifiers depending on the characteristics determined for these identifiers, and sequentially processing or despatching the messages from the buffer memory in the sequence they were sorted.