Roadian Htx Rh5 Highway Terrain. The Roadian HTX RH5 contains a four-channel groove design in forward direction to enhance drainage and hydroplaning performance on wet roads. The three- and four-division tread design improves grip while enhancing wear performance. The reinforced shoulder block design results in improved cornering and handling, while a center rib block design fine-tunes grip and steering performance. *By request/order.