As a previous resident of DC,Philly, NYC, my simple answer is YES. We (all of the US because NYC is the financial/media capital) do need bothj full rehab of the existing tunnels and an asdditional two in order to reasonably operate the growing passenger travel in that corridor. The existing PATH tunnels do not have excess capacity to absorb riders if the Amtrak tunnels fail. While Brokklynites are pleased that Prince Andrew (may have) found a less disruptive and genuinely workable method for repairing the Canarsie (14th St L train) tunnels, they are only 2 of 18 tunnel/bridge tracks linking downtown Brooklyn to lower Manhattan and not the major ones by ridership count. Meanwhile the Lincoln Tunnels (six lanes often run 4 and 2 in direction of rush) likewise do not have excess capacity, and they lead to a building every bit as run down as our Transbay Terminal was, which also needs to be replaced. Just remember that the "Gateway" tunnel project could easily be afforded by canceling a few F35s and other DOD toys.