It would take a major shift in national road culture. Impetus for that change might be $10/liter for fuel. Serious insurance problems/premiums for poor road usage. Some percieved reward for 'doing it right' regardless of how 'right' that might actually be. The change might occur swiftly due to serious needs. Our it might take 20+yrs due to the necessary time for society to morph into a new perspective. I have always suspected that it would take a variety of needs with 2 or 3 being the most obvious. No matter how bad any metro gridlock becomes the 'haves' will want it to go their way. And the hoi polloi will have to fight for whatever makes sense to them. Cheap transportation with good flow is not on any politicians/authorities radar unless they get a piece of the pie. Not exactly CS&M. But that seems to be what it will boil down to before we can expect the Enlightenment&Rapture of filtering and the like here in the States.
The cagers really changed for the better when fuel costs rose to $5+/gal in chicagoland a few years ago. I would never have predicted that if I wasn't here to see it for myself. The police revenue sharing plan took a nose dive as speeding tickets disappeared and they had to cite lesser infractions more frequently and erroneously to make up the shortfall. Bikers got a lot more attention which was a downside that really interfered with the joy of less traffic idiocy. At the time, I was actually looking forward to see what would happen if fuel hit $6 or $7 per gallon. Not that I would really like to live at that price without some significant societal 'rewards for being on the bike'.
Still, I do believe that we bikers should whine for filtering et al at every opp to keep it on the front burner of the pols. We do get a little grease for our wheel now and then. Recently, ILL got 'left on red' when the induction loop didn't trigger the signal. This is good for the surrounding 'burbs even though it is still not allowed in chicago limits. We always had this 'malfunctioning light' plea in court where we couldn't prove anything and got hosed if we tried it. The difference now is that the local gendarmes are less likely to write the cite. ymmv
"beware the grease mud. for therein lies the skid demon."-memory from an old Honda safety pamphlet