Will I Lose My License If A Blood or Urine Test Shows I Smoked Marijuana Before Driving?

Posted On October 06, 2011 by Daniel Koewler

There are two types of punishment the state can impose on a driver who allegedly operated a motor vehicle while impaired by alcohol or a controlled substance â?? although not all controlled substances are viewed equally. In Minnesota, the state cannot revoke your license to drive (one type of punishment) based solely on a positive blood or urine test for marijuana under Minnesota's Implied Consent laws. However, if a prosecutor charges you with the crime of driving while impaired (the second type of punishment) you will lose your license if convicted.

Minnesota has two methods of taking your license in this situation: through the Minnesota Implied Consent Act (civil driver's license revocation) and as a direct consequence if you are convicted of a crime.

Civil Driver's License Revocation

Minnesota's Implied Consent Act permits the state to revoke a driver's license to drive when a driver's alcohol concentration is .08 or more or when a blood or urine test detects any amount of most drugs or their metabolites, including prescription medications. As we discussed recently, the state may take the license even before the driver goes to court under the Implied Consent Act.

However, Minnesota treats marijuana differently from other drugs and alcohol. It cannot take away a person's license to drive under this law when blood or urine tests detect the presence of marijuana under any circumstances.

Criminal DWI Laws

So, in Minnesota, it is not, under the Implied Consent Laws, automatically a crime to drive a vehicle with marijuana in your blood or urine. Unlike other drugs, Minnesota does not make it a crime to have marijuana in a driver's system â?? meaning that there is no "per se| limit for marijuana. While the legal driving limit for alcohol is .08, and any amount of methamphetamine will provide a basis to charge someone with DWI, there is no minimum (or even a maximum) amount of marijuana that you can have in your system before it is illegal to drive.

This isn't to say you can feel free to toke up prior to driving, because it is still a crime to drive while "under the influence " of marijuana. If a person is actually impaired by the use of marijuana at the time they are driving, they can and probably will be charged with DWI. However, unless you plead guilty to such a charge, it is extremely difficult for a prosecutor in most cases to meet the burden of proving guilt beyond a reasonable doubt. If the matter goes to a jury, a good defense attorney can often suppress the results of any blood or urine tests, as the scientific community is in agreement that evidence of prior marijuana consumption simply does not have any bearing on whether or not someone was actually impaired by marijuana. And without those test results, the prosecutor's case is usually pretty weak. While it is never a good idea to drive a vehicle while tired, texting, after consuming alcohol, or with any sort of "hard" narcotic in your system, Minnesota has crafted its laws in such a way so as to make it easier to avoid a license revocation for those drivers who may have recreationally used marijuana in the past (which, let me make clear, is a crime in Minnesota) but who were not impaired at the time they were actually driving.