Nine fully instrumented low-volume flexible pavement sections were tested at the University of Illinois to evaluate the effect of three types of tire configurations on geogridreinforced pavements. The nine sections were divided into three cells comprised of 76 mm hot-mix asphalt (HMA) placed on 203, 305, and 457 mm aggregate layers, respectively. Geogridreinforcement was incorporated in at least one section in each cell. The pavement was instrumented during construction with pressure cells, strain gauges, LVDTs, thermocouples, piezometers, and time domain reflectometers. The test sections were exposed to accelerated loading. The tires used for loading were dual-tire assembly and 425 and 455 wide-base tires at five loading levels and two speeds. The study found that the 455 wide-base tire caused greater transverse strain in the thin HMA layer than the conventional dual-tire assembly when relatively thin granular layer is used on weak subgrade. However, as the supporting granular base layer stiffness increases, the difference in strain diminishes. It was evident that the new generation of 455 wide-base tire caused less damage to the low-volume flexible pavements than the old generation 425 wide-base tires. The measured longitudinal deflection in the base layer and vertical deflection in the subgrade were significantly lower for the 455 wide-base tire and dual-tire assembly when compared to the 425 wide- base tire. As the supporting base layer stiffness increases, the wide-base 455 tire's and the dual-tire assembly's overall effects on the pavement become similar for different loading conditions.