Is Ohio’s Marijuana “Drugged Driving Per Se” OVI Law Constitutional?

A recent Ohio Court of Appeals decision – State v. Schulz, 2015-Ohio-2252 – considered whether Ohio’s drugged driving law is constitutional.  Specifically, Ohio’s OVI law makes it a crime to drive with more than 35 ng/ml of marijuana metabolite in the driver’s urine.  If a urine test is over this