You can find information about blood concentration levels for drug driving offences in the Land Transport Act 1998. The Act has a schedule that lists the high-risk levels for different drugs. These levels are measured in nanograms per millilitre (ng/ml) of blood. You can also find tolerance levels for these drugs in the same schedule. Tolerance levels are lower than high-risk levels. The schedule lists the tolerance levels for each drug in ng/ml. The Land Transport Act 1998 is empowered by sections like ss 2, 167AAA, and 167AAB. The schedule helps you understand the blood concentration levels for drug driving offences. It is part of the Land Transport Act 1998.