Compact Parking Puzzle

This is a new parking area at the UO (underneath the new Education building). Why did they designate the spaces in the closest row "compact" instead of just making them as wide as the spaces on the other side? If you look at the lines around the support columns, you'll see that the space between them is of different widths - it's narrower on the upper row of spaces. There's no apparent reason why they couldn't have made the spaces in the closest row just as wide as in the upper row of spaces -- the total  number of spaces is identical in both rows, so they didn't gain a single space from making them narrower (because they can only get three spaces between each of the  evenly spaced sets of columns either way). It doesn't seem to be because of the space available for backing out differs, they simply chose to make one set of spaces smaller and designate them as for compact cars only. Why not make both sets of spaces as wide as possible? They can't possibly think that this will cause people to choose different size cars, can they? I must be missing something obvious.