Extra Credit opportunity:
A driver is headed north on a long, straight highway and sees this sign:
Nearville 150 miles
Farville 160 miles
Then, surprisingly, an hour later she sees this apparently inconsistent sign on the same highway:
Nearville 100 miles
Farville 109 miles
How can this be possible? [The signs are correct; the terrain is flat; neither town moves its boundary; there is no change in route.]
Hint:
Not all towns are directly beside a highway.