I just learned something that is surprising. Have you noticed that they put traffic lights and drawbridge gates up near the Paerdegat Basin Bridge several years ago. I secretly suspected that the contractor put them in the wrong spot, instead of at the Mill Basin Bridge. The Times had an explanation of this several years ago, which didn't convince me.
In looking it up again, I found another explanation for the gates, which is equally strange.
It's in this article, that I just became aware of plans to replace 7 of the Belt Parkway bridges, including Mill Basin, Paerdegat Basin and the Gerittsen Beach overpass. Interestingly, the new Mill Basin Bridge will not be a drawbridge.
The following article reports that the cost of replacing these bridges will be $500 million.