The case of the missing traffic growth in the Rochester - Minneapolis Corridor

Elizabeth Baier reports for MPR News: Mpls.-Rochester rail plans find no love in rural SE Minnesota. She writes:

"Traffic on 52 has grown steadily and that's expected to continue. Volume could nearly double to about 87,000 vehicles a day by 2025, up from 47,000 in 2000, according to a 2010 Highway 52 corridor study by MnDOT (.pdf)."

The relevant quote from the referred to 2002 study is  Page ES-1 "

"Traffic volumes on Highway 52 have increased steadily and are projected to reach between 29,125 and 86,775 vehicles per day by 2025, up from 17,550 to 46,800 in 2000."

Except, when you look at the actual MnDOT Traffic Data maps, the AADT on Highway 52 is  31,500 just outside of Rochester, is still well under 20,000 in Goodhue County between Rochester and the Twin Cities, and isn't above 40,000 until you get into the Twin Cities suburb of Rosemount, which is clearly due to daily commuting, not inter-city travel. And I will remind everyone, this year is 2015 (the counts are probably a couple of years old on this map), not 2000, more than halfway to 2025. Sure, things could change between 2015 and 2025, and traffic growth could skyrocket. The price of gasoline could become negative, and people get paid to fill up their tanks. On the other hand, maybe projections based on trends from the 1990s and earlier could stand to be updated a bit. Maybe a doubling of traffic over 25 years when population growth is under 1 percent a year  (i.e. population doubles every 70 years or so) was a bit hyperbolic.

The congestion-reducing claims for this rail line are unsupported, the existing highway route is uncongested, numerous improvements have already been made, and a few more grade separations and it is a full-fledged freeway. Highway 52 could handle more traffic if traffic were to actually grow.