The largest commercial jetliner ever attempted by Boeing, the 747-8, an extended version of its wide-body predecessor, is going to take longer to build than previously thought. Boeing executives thought it would be done this year, now it may not be until 2011. It's also running over budget.

Thom Neff, one of the city's consultants reviewing plans for the deep-bore tunnel, draws a parallel between Boeing's most ambitious aircraft and Seattle deep-bore tunnel. "It is years late and hundreds of millions over budget," Neff said last week. "Well, one reason is that it was beyond precedent." Likewise, he says it's unlikely that the tunnel could come in on time and on budget. "The real key here is we are beyond precedent. There has never been a tunnel of this diameter in the history of the world," Neff said.

This isn't to say that the tunnel can't be built. Or that the Boeing plane can't be built. They probably can be built. We just need a good plan for, like, who pays for them.