You can find an interesting set of charts analyzing vehicle miles traveled based on United States Government data, through April 2014, at:
Overall miles driven remain at 2004 levels. (I can't recall any traffic study correctly projecting this declining and stagnating reality during the years I sat on the Orange County Planning and Zoning Board). Vehicle miles traveled based on population growth, shown in the chart above, are the same as they were almost 20 years ago.
Here's the relationship to gasoline prices: