Oh yes, we've never actually gone out to the Sturgis Bike Rally, but we live in eastern So. Dak right along Interstate 90. You can hear the bikes going down the interstate day and night. It's quite exciting because so many stop here for food, gas, lodging, etc.
I'm not sure about the intersection you're referring to, but I'm guessing you're right on that. As long as you drive carefully, you should be fine. Oh and deer chasers are little ornaments that go on the front bumper of your car and they give a whistle as you drive. People can't hear them, but deer can and they run the opposite direction from them. We've commented on how they actually do work. Anyway, hope you have a wonderful and safe trip.