Cascadia Center’s Bruce Agnew on KUOW last week:

…there was no real media comparison to the tunnels completed here in Seattle, like the recently-completed Sound Transit Beacon Hill light rail tunnel, which came in on time and on budget.

The Beacon Hill tunnel on budget? Not by a long shot.

Here’s what really happened. When the tunnel project went out to bid, Sound Transit’s engineers estimated that the project would cost $238.6 million. (Seattle Times coverage here; Seattle P-I coverage here). But Obayashi Corporation won the contract with a low bid of $280 million, a 17 percent increase. During construction, the project’s costs subsequently escalated the contract to $309 million for a total cost overrun of 30 percent. (Source: Sound Transit, “Progress Report: Link Light Rail,” August 2009, p. 17, not available online.)  A subsequent Sound Transit progress report, for October 2009, shows the contract costs escalating further, to $311 million.

So, in the end, the final bill for the tunnel wound up being 30 percent more than Sound Transit projected when it sent the project out for bidding.

This isn’t a question of nuance or interpretation. It’s a matter of facts on the public record.  The only way that you can say that the tunnel came in “on budget” is by referring to a cost estimate made well after Sound Transit made its estimates—a “budget” that already accounts for the 30 percent cost overruns.

  • Cascadia is a big supporter of the proposed deep-bore tunnel under downtown, and they think that concerns about potential cost overruns are overblown. Agnew, for example, consistently compares the deep-bore to the I-90 Mount Baker tunnel, which really did come in under budget. It’s not a crazy comparison, but it is a selective one: the bored portion of the Mount Baker tunnel was only about one-sixth as long as the proposed downtown tunnel and that it was built with completely different technology and in a different place with very well-understood geology.

    The truth is, there is no apples to apples analogy between any two tunnels, even locally. That’s why Sightline published a report taking a more comprehensive look at Seattle-area tunneling projects. (Read the full report here: Cost Overruns for Seattle-area Tunnel Projects (pdf).)

    As it turns out, the under-budget Mt. Baker tunnel seems to be the exception. In fact, three of the four major recent tunneling projects in the area have gone over-budget—and by quite a lot. But Agnew himself dismissed the report on the radio:

    Ross Reynolds [host]: “I certainly saw some coverage. I think a think tank came out with a paper comparing the cost of the deep-bore tunnel to other tunnels in our area, and saying that it was going to cost a lot more than those tunnels.”

    Bruce Agnew: “Well, and that’s the problem, when the media doesn’t look into reports from think tanks. We’re one ourselves, but I think there’s a major difference in scope and technology, and difficulty, between those tunnels.

    But wait: I agree with Agnew here. Media, please make it a point to look into the reports from think tanks. And when you do, try to distinguish between those that look at actual, real world experience, and those that are based on wishful thinking.