Joseph Mazza said: The real policy or engineering plan that is needed is how to deal with diverted drivers and put them back on the the crowded thoroughfares of their own making.
I think this is absolutely true of the broader issues. Having lived here nearly two decades, I have seen an astounding (and disproportionate to local growth) increase in "non-local" or commuter/cut-through traffic.
The immediate issue, however, is whether 9th Ave or 7th Ave would make a better greenway. I am thoroughly convinced that 9th Ave would make a far safer and more pleasant greenway.