Between 1990 and 2001, highway miles in the U.S. grew by just 2% (Table 1076 of the 2003 Statistical Abstract).
In that time, U.S. population grew by 14%, passenger-miles via privately operated vehicles grew 33% and ton-miles via trucks grew 43%.
Give this mismatch of capacity and demand growth, traffic worsened. Over the 11-year span, worktrip travel times (privately operated vehicles) went up by 12% if you live in the suburbs and 20% if you lived in central cities (NPTS/NHTS data). Yet, suburban population grew by 55% while the central cities as a group lost population in the interval.
And the highways are mismanaged; access is mostly free and rationing is by crowding.
The glass is apparently half-full. Some have given credit to land market flexibility ("sprawl") that has allowed job sites and workers to co-locate in the suburbs.
Yet, as the sage said: "There's always something." As mentioned in yesterday's post, the "Smart Growth" game is now to apply more top-down planning so that flexibility can be replaced with management.
It's back to the Progressive Era in some quarters.