After Rick Scott rejected the Florida high-speed rail funds, a bunch of states as well as Amtrak applied for the redirected funds. The money has just been redistributed – see breakdown here. New York State applied for $300 million to grade-separate a junction between Amtrak and the LIRR, which it spins as an important capacity upgrade and which some online commenters have misinterpreted as a speed upgrade. Let me dispel the myth here.

The track map of the LIRR (link scrubbed for copyright reasons) shows clearly that, in the westbound direction, the junction has no conflicts. Amtrak trains (blue) using the northern tunnel pair to Penn Station have no conflicts with any other trains, except for other trains using the same tunnels. This is not a grade crossing, but a simple switch. In the eastbound direction, trains using the northern tunnels do have an at-grade junction with LIRR trains (purple) – but only trains going to a track farther north than the tunnels to Penn Station, and those all stub-end at Hunterspoint Avenue or Long Island City.

There aren’t a lot of trains going to Hunterspoint or Long Island City: at the peak, only 5 per hour, and of those one uses the Montauk Line, so we’re really talking about 4 trains per hour; Amtrak never runs more than 2 trains per hour to New York from the east. To put things in perspective, the 3 and 5 train on the subway have more than 10 trains per hour each and have a similar conflict in Brooklyn. What’s more, Hunterspoint’s main use is that it has an easy subway connection to Manhattan’s East Side, so once East Side Access opens and LIRR trains can go to Grand Central, traffic there will go down even more, making the flat junction even less relevant than it is today.

So the $300 million the state applied to has no relevance to either Amtrak or LIRR traffic. The only use is to let Amtrak use the southern tunnel pair to Penn Station without conflicts. Since Amtrak can already use the northern tunnels without any conflict apart from the one mentioned above, it is a pure nice-to-have. It would be good for operational flexibility if the tunnels were at capacity, but they aren’t: total LIRR plus Amtrak traffic into Penn Station peaks at 37 trains between 8 and 9 am, where the capacity of the tunnels is about 50 – and as with Hunterspoint traffic, Penn Station LIRR traffic will go down once East Side Access opens.