A new hydraulic tube structure for WIM sensor of a new generation is presented in this paper. The double-tube structure has been developed in order to improve the performance of the hydraulic load cell. The double-tube structure hydraulic element could be reduced by 46% in pressure changes according to temperature compared to a single-tube structure. In addition to the nonlinearity can be reduced by 67.19% at the same load condition. The hydraulic load cell shows an excellent linearity and measurement accuracy as the result of the static load test.