The Port of Long Beach has to come up with a lot of cash, fast and that may mean tolls on the Gerald Desmond Bridge.

When the $286.5 billion federal transportation bill was passed by Congress in July, the port only got $100 million of the $350 million it had requested to rebuild the aging bridge, a vital trucking conduit from Terminal Island to downtown Long Beach.

Given the exploding container traffic at the port, officials had been hoping to get their entire request filled. Now they are studying alternative means of raising the rest of the money.

“We definitely still want this project. It’s not clear how to fund it,” said port spokesman Art Wong. “We’re looking at other sources of funding, and we’re doing studies on tolls for the bridge.”

The port is expected to release a report this month that would lay out possible toll fees as well as other sources of revenue for the project, which is expected to total $760 million.

In recent years, the 40-year old bridge has become a bottleneck, exacerbating traffic and pollution on the chronically congested Long Beach (710) Freeway. The bridge now has two lanes in each direction. Any reconstruction would add at least one lane in each direction.

There’s another reason for need to rebuild: The largest container ships can barely fit under its spans. And the new generation of even larger “megaships” ferrying in goods from China won’t be able to get through.

So far the ports of Long Beach and Los Angeles have set aside $40 million toward the reconstruction. They hope that additional money will come from state and local transportation agencies. However, if the $250 million federal shortfall is not made up, the project which port officials had hoped to finish in five years may have to be stretched out. On top of all that, bridge maintenance has been falling behind.

“We’ve known there was a problem for years,” Wong said. “We’ve put off major upgrades on the bridge, like painting or retrofitting it for maybe five years now. Instead we wanted to do a major reconstruction.”