Do you hear the traffic/vehicles from the I-84 or if the train comes through?

Yes to traffic and the train.

Traffic was not a problem. We did hear the train pass a couple of times, but it wasn't that bad. We stayed there 2 nights ago. We are considering staying there again on the way home

During the day yes, but at night the traffic dies down on I-84 and the trains are not nearly as loud. When we went camping we were hesitant about that as well. However, either of us woke up from the sounds of the trains or traffic. My boyfriend is kind of a light sleeper and he said he never woke up from them. Hope this helps!