The California Department of Transportation is in some sense officially recognizing the law of induced demand on roadway expansion and the conclusion that we can't build our way out of congestion with new capacity.
|CalDOT's research page|
ODOT, our local MPO, and our City haven't quite figured this out yet.
But more and more state DOTs and local governments are finding that drivers fill new roads and that the apparent "congestion relief" only works for a short period of time. Trying to solve congestion through more roads and through wider roads just leads to more congestion. It's circular and it's not actually a solution. Moreover, it's an intensely expensive non-solution. Just a waste.
If we want to reduce congestion, we need to consider tools like congestion pricing, better transit, better land use to place destinations closer together, better walking and biking. We need to make it easy to see driving as the transportation choice of excess rather than the choice of economy, prudence, and convenience.