Those numbers are the difference between "An average American commuting to and from work in their SUV" versus "the same person making the same commute on a transit bus." It's a pretty compelling visual image of just how much fuel we can use in a day. The full press release is at the "Read" link.
I chose the picture above (from Flickr) because, yeah, it has a bus in it, but it also shows a form of transportation that uses even less fuel per commute. Two cups of coffee, maybe.
[Source: First Transit]