Hello,
I actually went through this exact situation and asked a pharmacist about this.
I am currently taking 2700mg of neurontin and WAS taking tramadol before I got my stimulator. The pharmacist told me that if you were to get in an accident or if you're acting impaired, the police will and can test you and charge you with opioid use or driving under the influence. Tramadol is an opioid. It may not be as hard as others, but nontheless.
Now, I did drive on tramadol because I took one in the am, lunch and pm to keep a blood level. I am working full-time so I had no choice. That is the main reason why I did the stimulator. I could not function on the tramadol, but I couldn't be without anything either. I was sleeping through meetings, etc.
Just a side note on the tramadol. When I had my stimulator implanted I needed to get off of the tramadol. I had major withdrawal issues. So, just a comment that it does have addictive qualities where your body depends on it.
Good luck fellow Minnesotan.