so besides leaving some low capacity, slow roads above ground, let's put a few high capacity, fast roads underground (we could call them lowways!) along with a bunch of underground parking. sure, it's expensive but in a wealthy high density area like market street, we can afford it. and yes, price in the externalities and use the money to build/maintain. best of all worlds! (better solutions probably exist, so let's find 'em)
ps - dockless electric bikes in SF totally beat driving, ride hailing, or public transit for me.