H/T D.K. James Fallows writes: Two Notes on Infrastructure and Going to Hell
... Delaware's two distinguishing traits: shamelessly milking I-95 traffic with highway-robbery toll booths, and cell-phone black hole, at least near Amtrak routes. Maybe they're mad about the lost tolls.
Indeed, Delaware achieves more of its transportation revenue from tolls than any other state. Why do they do this? As my dad would say "because they can." They probably have a greater share of through (non-resident) trips on their roads than any other state, being the second smallest. See Levinson, David (2001) Why States Toll: An Empirical Model of Finance Choice.