In the image below I’ve plotted the average gas price in each state for 4/25/07 (data from here) with and without state per-gallon taxes included. Without the taxes included, it becomes obvious that gas prices increase on the west coast, perhaps due to transportation costs? ( a quick search didn’t turn up any port-by-port oil import stats).
Image may be NSFW.
Clik here to view.
I created this using ruby-shapelib and rmagick as mentioned previously.
