The Avery/Mutoh printers on Avery reflective Omni are rated for 18 years, their lower reflective is 7-8 IIRC. The 3M HP latex machines are at 10 with Diamond Grade. Printing traffic reflective on and HP that doesn't allow you to raise the carriage sucks, I don't have the traffic setup on my 360s, but I have the profiles and it melts at times.
When I was in traffic
signs full time, most older cities would require 3m EC over lays and not deal with printed because that is how they have always done it since cut graphics were approved.