OK - Let's see here - $126,000,000 for 4 miles of a second main track, and two years to build it. $700,000 for an environmental review, so say $125m still left. Buy three more train sets and a few spares, say $50m of the cost. So that means the remaining $75m divided by four miles is "only" $18,750,000 per new mile of track to add that extra capacity or $3,550 per foot if you prefer. Even if some of that was being added for sound walls, landscaping, station platform changes, etc. the figure is still astronomically unbelievable. Oh - I forgot that federal grants often charge a 15% "administrative fee" so if $100m of that was a federal grant they would might to give back up to $15 million of that.

Now the only reason for a second main track is to either pass and run ahead of a slower train or to meet an opposing train. Is this that big of an issue? (I'm not familiar with Metrolink schedule, ops or track capacity.)

Wouldn't it be possible to simply add more cars to the existing express train? Even if the platforms are too short a car on each end with the doors locked out could easily add immediate capacity at a fraction of the cost. Or with some schedule adjustments simply run a second section assuming the equipment is available.

If this was a private industry losing customers due to poor service or lack of capacity, you could bet that they would have made changes in a hurry at a far more efficient cost.