Today there seem to be almost 30 flights daily between Seattle and Portland. Clearly a lot of people are making the trip. If you built a high-speed rail connection, a lot of people would take that. But how many would obviously depend heavily on how the price compared to the price of those flights. And that in turn would have a great deal to do with how we price pollution.
Meanwhile, back at the Infrastructurist....
Eric Jaffe posts this chart that shows that conventional rail (which it appears is all America will ever get) is even better, and that intercity buses blow them both off the road. He points out that once again, The Onion knows best.
More on modes:
Fate of High Speed Rail Uncertain after Election
New Governors Kill $1.2 Billion High Speed Rail Lines in Ohio & Wisconsin