A Big Break Through

As most people are certainly aware by now, the SR 99 TBM – Bertha – broke through on April 4, marking a big and welcomed milestone for the project. Most people are also aware of the many setbacks encountered on the project – most notably, of course, mechanical issues that led to a stoppage of tunneling for two years.

There was, understandably, much hand-wringing over whether the tunnel would ever be completed. And even now that tunneling has concluded, there no doubt will be hard-fought disputes over how costs related to repairs and delays will be paid for. But, with the finish line in sight, the end product is closer to becoming a reality and an asset for the community for years to come.

Artery before In this space in October 2015, I discussed the Central Artery/Tunnel project (aka “The Big Dig”) in Boston and whether it is a “successful” project. (I say “yes.”) Not surprisingly, the SR 99 tunnel drew comparisons to the Big Dig, another megaproject which famously ran over budget and schedule projections.

In the end, however, the Big Dig is serving its intended purpose of improving traffic flow, while at the same time improving the quality of life and creating new business opportunities. The green space created in the heart of the city breathes new life into downtown and reunites sections of the city that were cut apart with the construction of the old elevated highway that the tunnel replaced. Artery after

Similarly in Seattle, the SR 99 tunnel will replace the existing elevated highway that was in need of replacement in the wake of the Nisqually earthquake in 2001. By burying the highway and opening up the city core to the waterfront – the city’s most valuable asset – city planners have gone a long way toward improving the quality of life for the next 100 years or more.

Construction cost is not something to be simply dismissed, but 25, 50 or 100 years from now nobody will care about the cost. I recall reading old news reports from the initial operating segment of the New York City subway and seeing similar comments about the project cost being too expensive. More than 100 years later, it is hard to calculate the immense financial impact that the subway has on the city and the metropolitan area.

With the SR 99 tunnel, City planners had a once-in-a-lifetime opportunity to shape the landscape of Seattle for generations to come. Hopefully the opening of the tunnel to traffic and the dismantling of the viaduct will go a long way toward easing some of the pain and angst experienced during the tunnel construction.


After hosting the World Tunnel Congress in San Francisco last year, the Underground Construction Association of SME returned to its schedule of annual national shows with the Rapid Excavation and Tunneling Conference (RETC), June 4-7, in San Diego. While it was great for the USA to host the World Tunnel Congress for the first time in two decades, it was nice seeing some of the industry members who missed the international event.

In 2018, the North American Tunneling (NAT) conference returns to its regular schedule as it heads to Washington, D.C., June 24-27.


Jim Rush

Comments are closed here.