Here's a barebones timeline of Seattle's ongoing 2 mile tunnel through downtown. The project has been compared to the Boston 'Big Dig' which was projected at $2.8 billion, and wound up costing $22 billion.
Feb 28, 2001: Earthquake! A large elevated roadway that hugs downtown Seattle had been damaged. Almost immediately a debate began on how to respond. Debate, studies, proposals and counter proposals proceeded over the next 6 years.
March 13, 2007: a "
double-binary-advisory-ballot" was put before voters. Voters could choose between either a tunnel no tunnel), or a new viaduct (elevated) or no new viaduct. Voters threw up their hands and rejected all options. Building a new viaduct got the highest total of 43%. The tunnel got 30%
Jan 2008: Governor Christine Gregoire announced that the old viaduct would be torn down by 2012 due to the risk of disastrous collapse. As of now, it's still in service. Meanwhile Seattle Mayor Greg Nickels had been pushing for a tunnel, calling the viaduct the "
Big Ugly."
Jan 2009: It was announced that the city, state, county, and Port of Seattle had come to agreement on a $4.25 billion tunnel.
Oct 2011: Construction begins.
July 2013: Boring of the tunnel by the $80 million Hitachi "Big Bertha"
boring machine starts. Expected completion of the two mile tunnel: Fall 2014.
Aug 2013: Initial progress was slow--
24 feet in the first month. A Seattle Times columnist joked that a banana slug was faster. I did the calculation, and it was literally true.
Dec 2013: A labor dispute complicated things, but by Dec 2013 the machine had completed a little over 1000 feet--about 11% of the distance, but then unfortunately stopped after hitting a metal pipe, where it remained until just recently.
March 2015: Workers completed a 120 foot shaft down to the machine. It was hauled to the surface via crane. The machine will undergo repairs, and they hope to resume drilling in August 2015. Officials have been reluctant to make forecasts beyond that.