I was actually thinking today about what the current situation  about miles driven was, since it seems to predict GDP indicator to a good extent. Maybe this is the new sales slip indicator (in which the length of sales slip of a retail store are added up to figure economic activity).

But more to the point, are you sure about the second graph? It seems to me like the miles driven between 2005 and 2004 are not that far apart in the first graph, yet there's a huge drop that shows up in the second graph.

Wouldn't that 2005 line logically be lower in most points compared to the 2003 line for this data to be accurate?

Never mind. I just saw the year on year part for the second graph. A percent growth looks about right.