Negotiating traffic has been on my radar for some time. In most jurisdictions we don't have the necessary authority, training, or equipment, and to some degree self-control to move traffic.
I'd like to see that change in the coming years through the Time Task Force program.
I'm concerned that most tow operators have a frustration level that increases as a result of those three things. We tend to loose focus on safety as the seconds tick by.
As for the horn, use what you have if nothing else works.
I've always told myself to get there when I can, because if we, as towers refrain from bullying traffic then maybe, just maybe one day some TIM authority will say to themselves, "We need to get these guys here quicker and safer."
Remember, too that in a lot of cases like the one here, any other first responder will have just as much trouble moving traffic to get by a dumbass commuter.
Thoughts and opinions are my own and do not reflect the company I represent.