A rubber track assembly comprising a driving wheel, an idler wheel, an endless rubber track extending around the driving wheel and the idler wheel and having a plurality of rubber lugs formed on its outer circumference and a plurality of rubber guide projections formed on its inner surface, and a plurality of roller wheels arranged in contact with inner surface of the rubber track in a ground contact region thereof, each of the wheels has a pair of wheel portions formed at its opposite sides and spaced apart to be disposed at opposite sides of the guide projection for engaging the inner surface of the rubber track at the opposite sides of the guide projection. The rubber guide projection is provided with at least one low friction surface having a coefficient of friction lower than that of the rubber material of the rubber guide projection.