V2X message transmission method performed by terminal in wireless communication system, and terminal using same

A user equipment (UE) comprising:

• a transceiver configured to transmit and receive a radio signal;
• and
• a processor operated in association with the transceiver,
• wherein the processor is configured to:
• determine a priority of information related to a vehicle-to-X (V2X) communication,
• select a transmission time interval (TTI) based on the priority, and
• control the transceiver to transmit the information related to the V2X communication based on the selected TTI,
• wherein, when the information related to the V2X communication is information having a high priority, a first TTI is selected,
• wherein, when the information related to the V2X communication is information having a lower priority than the information having the high priority, a second TTI is selected,
• wherein a resource element of the first TTI is K times longer than a resource element of the second TTI in terms of a frequency, and
• wherein the resource element of the first TTI is 1/K times shorter than the resource element of the second TTI in terms of a time,
• where K is a positive integer other than 0.