Do the Math

Ok class, here is a math problem, who would like to go to the board and solve it?
Terrific Mary, here is the chalk, go to it...Here is the problem.

How much money will it cost motorists to navigate the BRB detour in the coming two and a half years? Here are some hints:

Average daily cars crossing bridge=24oo (conservative)
x 365
x 2.5
x 1 (mile detour from Potomac to Amity&Barry, your results may vary)
Divided by 20 (swag for average mileage of vehicles)
x 3.69 a gallon

And the answer is?