limits of radioactive waste for transpoorted

I needed to know what is the lowest amount of radioactive waste that can be shipped over open highways and that is still considered as rad waste. Exsample: Say I have a sample and I screen the sample for activity using a mulity smear counter, a frisker and a dose ratemeter and come up with back ground. Can I assume that this sample that came from a known radioactive site and that is labeled radioactive is non-radioactive according to the results of my instrumentation? Can I put this waste into another waste stream that is non-radioactive? (if so or not explain why and give limits to the levels both high range and low range of radioactive waste )