I have a small storm drain at the end of my driveway that was built by the town. The drain opening is 2'x2' and it looks to be about 2' deep. Like all the other storm drains in my neighborhood, mine is built from cinder blocks using very little mortar. Mine is the last in the run so I have one pipe leading away and no pipes leading in.

All of the storm drains like this on my town only last about 5 years before they start to crumble. By year 10 they are starting to collapse. The highway department does a crappy job repairing them and an even worse job repairing the asphalt on top. I'm not 100% sure why they fail so soon. Perhaps the salt eats away at the cinder blocks or maybe because they most likely didn't pour a footing.

Normally I wouldn't care too much, but I am expanding my driveway this summer. One side of the drain will touch the road, the other three sides will be bordered by my new driveway. After spending thousands of dollars, the last thing I want is to have to patch my driveway several years down the road.

Yes, I know I run the risk of pissing off the town, but I want to do the work because their workers clearly don't care about workmanship (I also know this because I used to work for them).

This is a small job so I know I can do it, but I want to make sure I do the best job possible. My plan is to dig down three feet, pour a footing, and build the four walls using cinder blocks. Then backfill with gravel and have the driveway guy pave over everything. My neighbor says that I should use Belgian blocks because salt won't eat away at them.

Do you guys have any suggestions?

Why are you doing the job yourself when the drive way crew can do a professional repair at the same time they work on your drive? The drain can be built with poured cement instead of cinder blocks, Good luck, Tom

I agree 100% with Tom but why not get the town's permission to let your contractor (or yourself) do the work? The contractor may refuse to work on the inlet without coordinating with the town, especially if he does a lot of the town's paving.
You know your town's procedures better than we do especially if you worked for them. Maybe they would insist upon building a crappy new one and make you pay for it if you talk to them. Is that the biggest risk?
The state highway agency I worked for would investigate if a supervisor saw or heard of unauthorized work being performed on a structure owned by them, then possibly require a permit including a fee, and assign an inspector.
Consider all the possibilities and make your decision.
I would talk to one or more of the contractors (get estimates if you haven't already) and see what they suggest. Maybe they will take care of getting the town's OK and let you build it--but it should be concrete if you have any delivery trucks of any kind using the driveway and don't forget the load from the paving equipment and trucks.