vic police roadside testing, page-6

Tim,

If I could answer part of that..

False negatives for cannabis is the big problem. Check the evaluation stats on the Vic Police website (summarised in one of HGR's presentations). Overall detection levels are very low compared to known use in the community. But main issue - cannabis detection only around 10% of amphet detection even though cannabis is the most common illicit drug (although amphets are not far behind). Detection for amphets and THC should have been similar.