Every day, 200,000 rail passengers cross the Hackensack River on a swiveling, groaning contraption that is barely suitable for human utility.

Most people know this: The Portal Bridge is not an archetype of modern transportation. The 961-foot swing truss nightmare predates the Titanic, Grand Central Terminal, the Panama Canal, and the Indy 500. It opened when Mark Twain and J.P. Morgan still breathed.

But President Trump is apparently oblivious of the mechanical crap shoot that is the Portal Bridge, where one malfunction can constipate the entire Northeast Corridor. He still needs a reminder that the best way to keep one-fifth of the U.S. economy humming is by replacing this erector-set reject from the Taft Administration with a modern crossing.

Gov. Murphy sent him the official memo Thursday, by pushing more than a half-billion dollars into the middle of the table and daring the president to match it.

It was the smartest and most pro-active measure New Jersey could take. Since March, we've heard Transportation secretary Elaine Chao droning on about how "the president is concerned about the viability" of the Gateway Project - which includes a new bridge - and how "New York and New Jersey have no skin in the game."

Now Murphy has sacrificed some skin - along with a few gallons of blood and some vital organs - by directing NJ Transit to issue $600 million in bonds to help fund the construction of a new $1.5 billion bridge.

Of the eight components to Gateway, none is more important than the Hudson Tunnels. But the Portal Bridge isn't far behind. It's a crucial part of the first phase of the $30 billion program, because whenever the existing span fails to close after maritime traffic passes beneath - which happens 15 percent of the time - that stretch of rickety track squatting 25 feet above the Hackensack River becomes the vortex from hell.

In March, the bridge got stuck in the open position during the morning rush, affecting NJ Transit and Amtrak service from Norfolk to Boston. The result: 150 delays or cancellations, with 66,000 travelers inconvenienced.

Now the trick is getting the Trump administration to live up to its promise not to sit on federal funding for a replacement. Almost nobody expects that to be easy. Murphy has done his best to eliminate federal foot-dragging, but industry experts still expect Trump to be dragged kicking and screaming to the table, while inventing another excuse to torpedo the federal funding obligation for this federally-owned bridge.

But the governor has created a viable path forward: "It's Murphy leading from the front," as Regional Plan Association president Tom Wright put it.

Somebody had to do it, because this 108-year-old relic is long past its expiration date. It was not built to handle 450 trains per day, or act as the linchpin for a 450-mile megalopolis. It's time to let it die, if only to avoid the pain it endures from the sledge-hammering it takes each time workers need to reposition the tracks.

The replacement project is shovel-ready. It was a priority long before anyone heard of ARC or Gateway. New Jersey knew it then, and it stands ready to address it now.

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