New Jersey officials are trying to determine how much of the $50 billion in federal Sandy aid will be used to help the state's transportation system recover from storm damage.

Rail cars, substations, tracks, and highways have to be repaired or replaced, says state Transportation Commissioner Jim Simpson.

He says all the sand the storm pushed ashore has compromised drainage systems along roadways.

"You can't take a Roto-Rooter ... sand does not come out of a drain, and then they start to collapse if you try to do something like that, and it's almost like concrete," he said Friday. "The sand, once it gets into the drains, is like concrete. So we're digging them up and we've got sinkholes around them we temporarily fill. So we've got a lot of work."

While he hopes New Jersey won't get hit again by a storm the magnitude of Sandy, Simpson says improvements to the transportation system are essential.

"We need to repair and or replace what was damaged, and we also need to improve," he said. "For every dollar we spend now, it's probably saving $10 or $20. Hopefully this is a 100- or 500-year storm or a storm of the millennium, but you never know so we've got to be ready."

One precautionary measure is a plan to expand rail yards near Linden and New Brunswick so trains could be stored there in future storms.