I did the route back in Sept. Stuck to the original route without any issues. There were a few trucks on SR 78 but you know when they're coming and they give you room.
I've never had issues with semis and wish Adventure Cycling would quit making them sound like their always some huge risk.
I too did the same route about 5 years ago and while we didn't have too much issue, we were mid-week. I talked to the convenience manager in Glamis and he said that the traffic is a lot worse on weekends. I am not worried so much about the semis as with the weekend RVers who may not know the edges of their rig while they haul a dune buggy (or two) on a trailer while heading home after a weekend of partying. We only had a couple of close encounters on that road mid-week but I sure would not want to ride it on a weekend.
Instead of ranting at ACA, you might draw up a suggested route on RWGPS and give ACA the pertinent info as to why it is better, i.e. it has shoulders, lower traffic count, X miles difference, more/less services, etc. so ACA can make a decision as to whether it makes sense overall. They are more than willing to listen to riders and locals and that is how the routes get a change usually. Sometimes I agree, sometimes I don't but they usually do it for safety reasons and I am all for that. Note that sometimes they reroute may not take place until the next map printing or only be shown in the Addendums page.
For instance, I proposed a few changes in my area due to the original route being on heavy traffic with no shoulders and showed them why I thought it was better. They rerouted the route as a result. Luckily, it was about the time the route was being reprinted.
Tailwinds, John