Possibly second frequency Milwaukee-Twin Cities

[Anderson]

There is no temporal separation requirement between Tier II trains like Acelas and freight. Only requirement is ACSES i.e. PTC. That is part of the reason that Tier II requires such additional weight for the added buff strength. There will be ROW separation requirements between Tier III trains and all other trains above 125mph, according to current proposals for the new Tier III requirements.

To elaborate, Tier II equipment is allowed to operate at upto 150/160mph other conditions permitting, and is allowed to commingle with all FRA compliant traffic at upto 150/160mph. Beyond that requires Tier III equipment and rules. Tier III equipment would be allowed to operate at a maximum speed of 125mph in commingled traffic. On dedicated trackage where there are no Tier I and Tier II equipment present, Tier III equipment would be allowed to operate at upto 220mph, or course track and other conditions permitting.

The temporal separation rules apply when equipment that does not comply with Tier I operates on FRA governed lines under a waiver, e.g. RiverLINE DMUs on FRA governed Bordentown secondary. That is done by temporally separating Tier I equipment operations from non-copliant operations. But even there parallel operation of the two on parallel unconnected trackage is allowed. Eventually it is likely that with PTC with some additional caveats, mixing might be allowed there too.

There is a short segment controlled by a single control point where such is already allowed as an experimental measure under a special waiver.

George will provide the details later perhaps, but roughly speaking, for 110mph considerable additional work needs to be done to upgrade grade crossings, and also inspection and maintenance schedules for tracks become much more stringent. For 125mph, for all practical purposes all grade crossings have to be removed. Beyond 125 something like ACSES is mandatory.

All jokes at UP's expense aside, isn't there at least time separation on those NEC segments where 150 MPH happens? i.e. We're not likely to see the Acela blowing past a moving freight train?

There is nothing in regulations that would prevent such. As a matter of normal practice it is unusual for freight trains to operate during heavier traffic daylight hours. However, between New Brunswick and Trenton it is not at all unusual to see Acelas blow by freights at 135, and that is not likely to change when speeds get bumped up to 150/160.

So if I read this right, a Tier II train could run with freight at 150 MPH but if the train is a more advanced model, you have to kick the freights and Tier II equipment off at 125 MPH? I'm going to say that such rules, right there, make me suspect that it would be a lot easier/simpler to simply not buy anything that is Tier III.

In all fairness, I think that most lines are likely to end up as technically "Emerging HSR" lines (the 79 MPH limit becoming 90 MPH...I've taken to mentally considering 90 MPH as conventional and 91-125 MPH as the "next stage").

One big problem in a lot of areas: What do you do with non-highway grade crossings? For an example, while you've only got a handful of grade crossings on the CSX Peninsula Subdivision up through about Route 199 on the north side of Williamsburg (you've got Harpersville Road, Industrial Park Drive, Yorktown Road at Lee Hall, North Henry Street right by the train station (a badly-stopped long train can block the road for the duration of the stop), Airport Road, and Rt. 646 up by 199, once you get past there you've got a lot of traditional "farm crossings" and rural road crossings (I can think of at least 3-4 of them). Unless you do a total rebuild on an alignment, it just doesn't make sense to even try to get rid of all of these.

Likewise, what counts as a sufficient "barrier crossing"? I'm guessing that your classic lowered gate isn't going to cut it here.

 

[jis]

If the Tier III rules get adopted as is then the only way to run anything above 150/160mph would be to meet Tier III rules. So if you decide you will never buy any Tier III equipment and build Tier III compliant track layout then you will never run any service faster than 150/160, I.e. no "High" Speed Railroad, only somewhat higher speed ones.

When the NEC was finally segregated and grade crossings removed as part of NECIP. Informal crossing were fenced shut. Currently the Keystone Corridor is going through the final exercise of grade crossing removal/replacement, though it will continue to have other crossings at lower speed limit areas, just like NEC east of New Haven has grade crossings and other crossings in lower speed limit areas.

Sufficient barrier for road crossing in 110 to 125mph territory have to use solid barriers like used on roads at airport secure area entry points, where the barrier rises from the road base and solidly block access. Ac car or truck that hits the barrier at speed will be substantially destroyed. No one has decided yet to keep such a grade crossing around.