(also posted at the rather low-traffic ACA forum (http://www.adventurecycling.org/forums/index.php?board=36.0))
According to Alaska's 2010 application to AASHTO (http://ballot.transportation.org/FileDownload.aspx?attachmentType=Item&ID=192), USBR 97 (not identified by number in the application) follows the Seward and Glenn Highways through Anchorage. But Google's mid-2011 Street View photos show 'pedestrians and bicycles prohibited' (http://maps.google.com/maps?hl=en&ll=61.182418,-149.861219&spn=0.009474,0.033023&gl=us&t=m&z=16&layer=c&cbll=61.182654,-149.8613&panoid=n_pIG4indBmVSZQfRwKHKQ&cbp=12,198.42,,2,2.81) signs on many freeway sections of these highways. There are certainly alternates open to bikes - Old Seward Highway to the south, and a sidepath along the Glenn Highway (not sure if it's plowed in winter). But the point is that nobody bothered to check the route - nobody at Alaska DOT and nobody at AASHTO (the ACA gets a pass because apparently they weren't consulted (http://blog.adventurecycling.org/2010/11/us-bicycle-route-report-from-aashtos.html)). It's not too surprising to me, since they've done the same sort of thing for U.S. Highways (https://www.aaroads.com/forum/index.php?topic=1681.msg37910#msg37910), but it's a little troubling.
Was this passed at one of AASHTO's regular meetings? I could see this being rubber-stamped to get it out of the way so they could focus on the multitudes of highway applications that they had to deal with as well. The USBR system has probably not been one of AASHTO's top priorities in a long time.
I love the route number.
but yes, it should be put onto the old roads whenever the freeway has bicycle prohibitions.