A plurality of main grooves extending from a tread center region including a tire equator to ground contact ends so as to be inclined with respect to a tire width direction are provided on a tread section at intervals in a tire circumferential direction. Sub-grooves extending in a direction crossing the tire width direction with a narrower groove width than the main grooves in the tread center region are provided. Tie bars connecting blocks separated by the sub-grooves are provided inside the sub-grooves.