Here's another reason to invest in rail transit along the I-5 corridor from Vancouver to Portland: the environment.
Of course it will cost billions, but we should begin the process with the money we have amassed in recent years. If we don't, we'll never be able to afford it. Ticket revenue would defray a portion of the cost, and productivity gains will help offset the cost.
If we add tolls along the corridor based on the amount of car traffic, the economics of a rail alternative would improve even more.