With New Jersey's Transportation Trust Fund scheduled to run out of cash this summer, the state is being dotted with shuttered bridges that will remain closed indefinitely.

Spencer Platt, Getty Images

Two recent examples took bridges out of commission in Dover Township, Morris County and Franklin Township, Somerset County. In both cases, the bridges were deemed unsafe, but the funds aren't available for repairs.

According to Bill Dressel, executive director of the New Jersey State League of Municipalities, the depletion of the TTF is one of the most pressing issues facing mayors and governing body officials in 2015.

He said "scores of mayors" are coming forward with concerns regarding infrastructure improvements.

"This is a train wreck that's on the verge of happening," Dressel said. "Public safety is at risk. This is a major problem."

Tom Bracken, chair of Forward New Jersey, said the recent bridge closures are a "screaming cry for action."

"ForwardNJ has been saying for months that hundreds of New Jersey's bridges are reaching the point of being totally unsafe and unfit for daily use by commuters," Bracken said in a press release. "It is past time that our leaders in Trenton take action and find a long-term, reliable, sustainable and constitutionally dedicated manner to fund the TTF."

Legislative leaders in New Jersey have discussed numerous ways to replenish the TTF, which pays for state road, bridge and transit projects, and doles out aid to counties and towns for the same purpose.

A gas tax hike has been proposed, and Gov. Chris Christie has said everything is on the table.

New Jersey Department of Transportation Commissioner Jamie Fox ordered an expedited review Tuesday of all structurally-deficient bridges in the Garden State. Steve Schapiro, a DOT spokesman, said there are 600 such bridges; a bit more than half are on county or municipal roads.

"We may have to close other bridges to ensure public safety," Schapiro said. "We won't really know until we conduct this review."