It’s illegal to refuse a roadside drug test due to a concept known as “implied consent.” This principle holds that as soon as you step into a car and begin to drive, you are under implied consent that you are physically and mentally able to operate the vehicle. This includes not driving while intoxicated.
Refusing a roadside alcohol test could lead to an immediate DUI charge, even if you were not intoxicated, and all the consequences that come with this charge.