Thanks, all, for your perspectives. I got curious about this yesterday... we have a number of these kinds of roads in town.
I look straight ahead and it's just a flat road. I look off to the side and it shows a pretty decent slant.
I checked my Garmin -yeah, I know- and it says it's around 3%
So, I got to thinking... is this a climb?
Something similar happens on a "real" (>6%) climb... look straight ahead and you feel like you're crawling.
Look to the side and you can see you're actually moving at a pretty good clip... and I only climb at around 6-8 mph