California bearing ratio

The California Bearing Ratio (CBR) is a measure of the strength of the subgrade of a road or other paved area, and of the materials used in its construction.

The ratio is measured using a standardized penetration test first developed by the California Division of Highways for highway engineering.^[1] Empirical tests measure the strength of the material and are not a true representation of the resilient modulus.^{[citation needed]}