One sets off for a morning drive on Thanksgiving. Upon entering the freeway, they find the normally traffic-congested road smooth and free-flowing. The journey takes a little more than half the time it usually would. They exclaim "Wow, the roads are empty this morning!"

I'm playing a bit of devils advocate, but it's not inconsistent to observe a typically congested resource X operating at a fraction of its capacity, and note the observation with "wow, X is _empty_".