I commute by train to New Haven on the same tracks that Acela uses.

The existing track corridor in New England is not appropriate for true high-speed train service. That really requires new right-of-ways, which would be extremely expensive in the Northeast.

There are currently plans for the next version of Acela but it is more about replacing aging equipment than any true speed upgrade. The Acela trains are almost 20 years old but I've never been on one as the price difference from the regular service isn't worth the small increase in time. Here are some numbers. I'm showing the cheapest "Saver" fares which are limited, must be purchased in advance, and have strict refund rules. I just picked November 4 as the date for advanced purchase (about +30 days):

NYC to Washington DC.

    Acela Non-Stop: $137, 2h37m
    Acela Regular:  $137, 2h57m (+20m from non-stop)
    NorthEast Reg:  $54,  3h25m (+48m from non-stop)

Here are Boston to D.C:

    Acela Non-Stop: $144, 6h39m
    Acela Regular:  $144, 7h5m  (+21m from non-stop)
    NorthEast Reg:  $81,  7h59m (+1h20m from non-stop)

Everyone swooning over the train infrastructure in China seems to overlook the raw power that the Chinese government wields to claim right-of-ways, fix labor rates, and so on. It is also almost impossible get a good sense of the financial structure of those projects. How much money was put into them? Could that money have been better spent elsewhere? What is the debt structure? The ROE? The environmental impact?

People in China that lose their homes to infrastructure projects do get compensated for it.

I think the bigger advantage for China is that the decision to run the track on some alignment doesn’t get litigated and re-litigated for years before construction is allowed to begin.

I would note that not only do you need to acquire a lot of property on straight lines, you need to do so while resolving to not benefit anywhere between your start and end points.

Non-stop is an important element of a truly fast train. Firstly because you don't want to be constantly stopping and starting, but also because you don't want to detour your route through a dozen cities which aren't conveniently on a straight-line route to your destination.

So if you want to make a train run as fast as possible between Boston, NYC and DC, you're telling Connecticut, New Jersey, Pennsylvania, Maryland, and maybe Delaware, "Hey, we want to take a big chunk of your land for our project, and no, we don't want our super-fast trains to stop at any of your cities, and we can't even run a slower train because making the tracks actually go through the right parts of your cities would slow down our fast trains too much."

Have fun with your negotiations!

That isn't true. You have multiple tracks for a reason. Generally, you have three separate trains on the same tracks and a sidetrack that goes into the cities or two tracks that split before the city and merge after the city.

1. Direct - They have the least stops and are the fastest. They don't go into towns. They go around them. 2. Express - They only stop at the largest towns. 3. Regular - They are the slowest and stop at every town.

You then use timing to make sure that they don't crash. The slow train will generally stop on the track and wait while the direct overtakes it (you don't want them both moving at the same time).

This isn't new. It's be around for 100 of years.

This is about routes, not lines or spacing.

If you have three cities on a perfectly straight line, you can run your high-speed trains as above.

If the city in the middle is not on a straight line path between the two end cities, now your train tracks need to curve to connect the three. If you make the curve a large enough, smooth enough curve, it won't hurt your maximum speed much, but when you're talking "1000 km/hr" ... and in any case, you're also adding miles to your route, and if you make your route 20% longer to weave from city to city along the way, you are also make it 20% slower.