ION Phase 2 - Cambridge's Light Rail Transit

[Bytor]

If you look at the chart on the previous page, you will see the route A option at $1.8M (top left figure), a roughly 20% increase from the pre-pandemic estimate.

Option A in the report is Fairway to Pinebush only. The previous roughly $1.2B cost estimate was for the construction of the entire length, option C in this report. So you can't really compare them like that and say Option A is a 20% increase from previous.

The preferred route is now C, though, which is $2.7B -- about 50% higher than A.

Which is 10 years worth of 8.5% inflation every year.

That roughly $1.2B we got previous was from, what, 2018? To get from $1.2B to $2.7B in 5 years is 17.7% inflation every year. That makes nosense is utterly ridiculous.

Even at the 6% that TaylorTBB mentioned above, it should only have grown to ~$1.6B.

The cost escalation (over about 12 years) is about $1B, taking it to about $3.7B. And then a 20% contingency/buffer to allow for cost overruns. And that's how we end up at about $4.5B.

That $998M "escalation" would be the equivalent of roughly 2.6% inflation for 12 years

It should be ~$1.6B plus ~$553M escalation for ~$2.16B, then 20% contingency of ~$432M for a total of ~$2.59B.