I've been waiting for this for a while, and it has now finally happened: Arizona DOT construction plans are now available online, at no charge, for currently advertised contracts.
http://www.azdot.gov/LegacyApplications/CNS/phone_sheet.asp
I am not sure when they went live, but suspect it was in the last month or so since there was no availability when I last checked sometime in February or March. This is an especially welcome addition since ADOT signing plans are clean and plentiful. There is no major sign rehabilitation contract currently under advertisement (the Flagstaff job currently listed is small signs work only and the plans set is essentially a spreadsheet printout), but I still count 15 pattern-accurate sign panel detail sheets among the 16 projects currently available, most of which are for designable construction detour signs.
As for Arizona's neighboring US states, here is the current state of play:
CA--online (free) since 2001
NV--QuestCDN (pay service, $600/year) at letting since 2011; online (free) after award since 2013
UT--online (free, but bowdlerized, with structure plans removed) since 2003
NM--Bid Express (pay service, $1620/year) since the late noughties
CO--no online availability
And for other states represented on the Mountain West board:
MT--online (free) since 2003
WY--QuestCDN since 2008