After many years of practice, public discussions of traffic and transportation in the U.S. have almost jelled into a standard format. The two sides divide roughly as follows:
1. Those who have the any understanding of markets argue that the accurate pricing of access to roads and parking is the no-brainer remedy and that nothing else comes close.
2. Those to whom markets remain impossibly exotic argue for anything but pricing, including high-cost rail transit -- which has, either, a narrowly rational (but unacknowledged) political pork basis or an irrational (romantic) basis in the urban fanatsies of the uninformed
The two camps have, for the most part, been unable to communicate.
Trying to bridge the gap, I used to cite the factoid that 50% of morning peak travel is for non-work purposes; while 60-70% of afternoon travel is for non-work. So there are may be more than a few trips that could be tolled off the peaks -- before we build again.
I was wrong. The 2001 National Household Travel Survey (NHTS) includes data that show the non-work share of person-trips in the Mon-Thurs morning peak (6-9 am) is actually 62%; the afternoon (4-7 pm) non-work share is 76%. These numbers have jumped since the last time I looked, making the case for peak-load pricing stronger than ever.