You might consider adding more fields to your DB for diff't tunnel specs (horsepower, # of doors, indoor/outdoor, etc), as well as notes. For instance, at the tunnel I fly in, their advertised rate is one thing...but if you buy from them at a boogie, you get a huge discount.
(Some tunnels also charge you for DVDs, etc, and some don't - those sorts of perks can add up.)
Again, great idea.
**edited because I looked again and saw you already had a place for 'tunnel diameter'...
(This post was edited by LloydDobbler on Jan 23, 2009, 10:37 AM)