Educating the auto drivers would be the big hurdle.
As it stands now, there is a large percent of people who get pissed when they see motorcycles gaining any advantage in a congested traffic situation.
I don't see any Federal legislation on something like this. Rules like this are usually left to The States.
If it were enacted, I think a max top speed of something like 45mph while splitting would be a good idea.
I've seen some real nutters in places like D.C. splitting at 70+mph. Shite like that just pisses people off...
Rocker59 (aka guzzimike), Aux Arcs
Moto Guzzi Sport 1100
"Do what you can, with what you have, where you are." - Theodore Roosevelt