It's silly for the Alma-Bentonville freeway to be numbered I-540 when it's ultimately going to be numbered I-49 ... Why not just get it over with and name it I-49 as soon as possible?
I agree. First, at least
AHTD tried to change the designation from I-540 to I-49 in 2007 but got shot down by AASHTO (page 2/6 of pdf). Missouri also got shot down in 2007 (page 3/6 of pdf). However,
Missouri came back to AASHTO in 2011 and I-49 shields will be uncovered in Missouri in December 2012 (page 6/8 of pdf).
Missouri I-49 signage will create a new reality: a huge
interstate I-49 "gap" from Pineville, Missouri to Shreveport, Louisiana. In funding priority terms, a new reality of tight money is that corridors of "regional and national significance" will receive priority for funding. With that in mind, and with two sections of the Arkansas Bella Vista Bypass having been let/ now under construction, I think AHTD would be crazy to not go back to AASHTO for a designation change (as an aside, Missouri's conditional signage approval includes the unlet/ no current construction Missouri section of the Bella Vista Bypass).
I understand that, if you look at it from a purely Arkansas perspective, then the reality that the Arkansas I-30 to I-40 gap will be around for a long time is an argument for not signing it. However, from the regional/ national perspective, AASHTO has already blessed the "big gap" between Missouri and Louisiana. Why not shrink the "big gap" by changing I-540 to I-49 (as well as signing I-49 from Shreveport to the Texas state line)? Shrinking the "big gap" on a map will drive home the point to even the most simple-minded Congressperson that I-49 is a corridor of regional and national significance. Plus, the smaller the gap, the more that completion of I-49 seems "doable", which in turn stengthens the argument for I-49 funding. After all, Pennsylvania and New Jersey have survived the I-95 "gap" for a seeming eternity.
As far as driver confusion goes, in a very short period of time drivers driving on I-49 south from Missouri will wonder why the same interstate is suddenly numbered I-540 (did we mistakenly get on a bypass?; I-40 is nowhere near Bella Vista

). I think the locals living along I-540 would welcome the number change, especially if it would make their interstate more "important" in funding terms. AHTD should follow MoDOT's lead and make a return visit to AASHTO.