"Even the slightest slowdown can interfere with the daily routines of the approximately 150,000 New Jersey Transit passengers who cross the bridge each weekday. Nearly 400 New Jersey Transit trains and 103 Amtrak trains use the bridge daily. Because of its structure, trains can travel only 60 miles per hour on the bridge, compared with 90 miles per hour on tracks nearby.
The 961-foot Portal Bridge, which sits on a turntable, has only two tracks. And because its lowest beams are only 23 feet above the river, the bridge must swing open almost daily to allow commercial boats to pass. That delays trains traveling between Pennsylvania Station in Manhattan and all points west during non-peak hours on average about 20 minutes."
Replacement plans call for two bridges to be built with room for five tracks. One bridge, with three tracks to the north of the existing bridge, will be high enough that it will not have to open for boats. The second, with two tracks, to the south of Portal, will still have to open, but only "a few times a year."The project, which is scheduled for completion in 2014, will be carries out at the same time that new tunnels for the $8.7 billion "Access to the Region's Core" project are being built, Tracks using the bridges will feed into the new tunnels which will run to an auxiliary NJ Transit terminal just north of Manhattan's Pennsylvania Station., as well as the existing Hudson River tunnels currently used by Amtrak and NJ Transit.
When the projects are completed, NJ Transit will be able to add service on its North Jersey Coast and Morris & Essex routes and run Raritan Valley line trains into Manhattan. The projects will also benefit riders on Metro North's Port Jervis line, who are subjected to bridge-related delays when they transfer at Seacaucus Junction for trains to Penn Station. As part of Access to the Region's Core, Port Jervis, Bergen County Line and Pascack Valley Line trains will gain access to the Hudson River tunnels, as well.