Planks for the range of standard 600mm wide solid and voided planks I-Girders for stringer beam sections Super-Ts for the newly developed thin walled hollow boxed sections Note:   The above span ranges are typical for most highway bridges in Australia. For special routes where SM1600 design loads are required, the maximum spans should be adjusted as follows: Super-Ts reduce by 2-3m I-Girders reduce by 5m Planks reduce by 2-3m.