Puckdropper puckdropper(at)yahoo(dot)com wrote in
eb.com:

It may be concrete ties are coming down in life cycle cost enough that
their advantages over wood ties are worth the investment, or the UP is
planning for possible higher speed rail.

As I noted earlier, concrete ties have been the norm for mainlines
for the last 20 years or so. With a heavily used track, the rail
cuts into wood ties and they have to be replaced every couple of
years. The counterpart to that is that concrete ties are very
stiff, so the subroadbed has to be built very strong, so that the
ties don't flex at all. For a less-used secondary line, it makes
more sense to put less money into the roadbed, and use wood ties
which will flex without cracking.

Train speeds much over highway
speeds (70 in many places, 75 in others) require the use of concrete
ties.

No, you can use wood or concrete at any speed. It's the weight
and number of trains that makes a difference, not the speed
(speed limit for freight trains is 69mph, for passenger 79mph
except for a handful of "high speed" lines. As you might guess
by the weird numbers, those are set by the Federal government).

Sure would be nice to have another option for those trips where
another state is just in the way. (IL to OK has MO in the way. I44
in MO is interesting, though.)

With airline seats being designed for 12 year old children, yeah,
having an adult alternative would certainly be nice :-)

John