I'll have a longer post with my personal highlights from last night's tunnel debate later, but in the meantime, city council Mike O'Brien sent me a copy of the letter King County Labor Council executive secretary David Freiboth and People's Waterfront Coalition founder Cary Moon were arguing about last night. (Moon insisted the letter, signed by the members of the viaduct stakeholder committee, endorsed the surface/transit option; Freiboth insisted, just as fervently, that it endorsed the deep-bore tunnel.)

Here's what the letter says, in relevant part:

Dear Governor Gregoire, Executive Sims and Mayor Nickels,

December 18, 2008

After considerable analysis, input and consultation with our constituencies we recommend & conclude the following:

• Move forward with an Alaskan Way Viaduct Replacement Plan that includes improvements to I-5, transit, surface streets and potential for construction of a deep bore tunnel.

• These improvements should move forward as soon as possible to mitigate removal of the Viaduct.

• The State’s contribution to the project should be capped at $2.8 billion.

• The region should be responsible for finding additional revenue for the project through variable tolling and other regional means to pay the extra construction costs of the project, including a potential bored tunnel.

• A state-funded Supplemental Environmental Impact Statement should include review of an I-5/surface/ transit hybrid, including the proposed building block investments. Sufficient funds should also be included within the SEIS for design and necessary environmental review of construction of a bored tunnel with a commitment to bring it to a record of decision.

My read on the letter is that there's enough room for interpretation that both sides can legitimately claim to be right. Tunnel opponents point out, correctly, that the letter explicitly endorsed making the improvements called for in the surface/transit/I-5 option and studying the entire proposal (which, incidentally, the state did not do). Tunnel proponents are also correct when they say the letter calls for studying the tunnel and building it if it's feasible. So, depending on how you interpret it, the letter can be read as an endorsement of the tunnel or an endorsement of the surface/transit option.

However, the letter also states explicitly that "the region" should pay for any costs over the state's $2.8 billion, "including a potential bored tunnel," which seems to contradict both sides' claims that they don't want local taxpayers to pay for cost overruns on the tunnel.