IIRC, they didn't raise it because of the crashes. It's a privately owned rail line and they don't care about that because the bridge itself wasn't being damaged. It needed to be renovated anyway so they raised it to be level with the nearby at-grade crossing while they were at it.
They won't because there is an old sewer main that runs underneath and according to the town is prohibitively expensive to reconcile all of that with the bridge lowering.
The rail line won't increase the height anymore because then it will cause a hump in the train tracks there.