A tire contact pressure study has been conducted to determine how different truck tire types respond to load and inflation parameters. The combination of tire type/size, loading, and inflation pressure determines the shape of the vertical contact pressure profile and the maximum contact pressure. Radial-ply truck tire contact pressures were generally higher than the bias-ply truck tire. Tire loading influenced shoulder region contact pressures whereas inflation pressure influenced center region contact pressures. The maximum level of vertical contact pressure was found to be as high as twice the tire inflation pressure.