Legislation to allow roadside drug testing has recently passed its third and final reading in Parliament - but concerns have been raised.

Some fear that people using ADHD medication could be caught out by the new roadside drug tests carried out by police.

AA Road Safety spokesperson Dylan Thomsen says testing devices in Australia don't generally pick up on ADHD medication or medicinal cannabis - so it's possible people won't need to worry.

"The law is also going to have a medical defence... so if you have a prescription and you're using it as prescribed, you shouldn't be looking at any fines or demerit points even if you did return a positive test." 

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