What I see is a substantial increase in VMT from 2003 to 2004, most of which took place on urban roads (with a lesser decline on rural roads).  I'd wonder if this was a result of job-seekers relocating to the urban sector.
VMT normally increases every year by about 3%.  So what happened 2003-2004 is a little on the low side, but still fairly normal.
Is the relocation of traffic to urban areas normal?