I understand the "trap" of multiplying a change from 8.0 to 9.4 mph to get a big number.  But, in roughly the same time frame as building the extra lanes to do that, what should a place like LA do? My wife grew up in "the valley" (as LA folks would say; here in Texas "the valley has to do the southernmost part of the Rio Grande).

The source feeding the road is NOT a compact circle, but a huge grid; the destination is NOT a compact downtown, but its own vast grid. It reminds me of taking a ferry from the west side of Puget Sound to the urban area (Seattle and suburbs) on the west side. Many of the friends that did that had a "beater car" on one side and their "real" car on the other. 

What steps (again, same or less time and money as a new lane) can LA take?