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Puget Sound Transportation Projects

Tacoma Narrows Bridge

Image: Bridge Lit up for the 4th of July

The Tacoma Narrows Bridge has a long and interesting history. Its collapse in 1940 led engineers to examine wind loads and aerodynamics when building such large projects in the future. The bridge opened up the Olympic Peninsula, and especially the Gig Harbor area to development. It also serves as a primary link to Bremerton and the Puget Sound Naval Shipyard. However, traffic loads now exceed the 4 lane, no shoulder, no median bridge. So in the 1990's a public-private partnership, the first in the state, was set up to build a second bridge, refurbish the first, expand SR 16 with carpool lanes, and charge a toll to cover construction costs.

The new bridge and associated projects have been completed as of 2008. The addition of tolls, especially with tolling being run by a private company, have led to many legal battles, primarily from Gig Harbor residents. However, the legal issues were resolved or dismissed a couple years ago and construction commenced. See my thoughts below for more about these battles and the tolling process.

both bridges open in 2008

The first Tacoma Narrows Bridge was built in the late 1930's to bridge a narrow strip of Puget Sound between Tacoma and the Olympic Peninsula. The original bridge was designed to established engineering standards, which called for a stiffened, inflexible structure. However, it was soon discovered that in the Narrows, the wind caught this stiffened bridge and made it act like an airplane wing. The bridge would bounce up and down, giving it the nickname "Galloping Gertie".

In November of 1940 a large windstorm blew through the Narrows. The bridge bounced up and down enough that it was closed to traffic. Soon afterwards the forces acting upon it became too great and the bridge tore itself apart, dropping the center span into the Narrows. It was rebuilt a few years later, now with very prominent holes in the decking and towers to allow for airflow. The bridges destruction led to the analysis of aerodynamic forces affecting major construction projects and is still discussed in civil engineering classes today.

Interesting Facts:

  • Destruction of the first bridge led to the examination of aerodynamic forces on major civil engineering projects.
  • New bridge will have the capability of being second-decked, either with more traffic lanes or for light rail/Bus Rapid Transit in the future.
  • The Tacoma Narrows is a big shelf between the upper and lower parts of Puget Sound. Because of this, currents can be up to 8 knots in the work zone during tidal changes

Thoughts:

While I understand the pain of having to pay a toll everyday to cross from the Gig Harbor side into Tacoma, and the understandable concern about a private company running this project, and possibly raising future tolls, the current tax climate in the state does not allow for public funds to build a project like this. And the current traffic on SR 16 is almost as bad as on SR 520, with backups extending miles in both directions for hours. One issue is that the Gig Harbor area did not become popular until after the first toll was removed. So yes, I could see a slight drop in property values in the near term, but I think over time it will enhance property values by allowing faster access. I also think tolls, already a standard for many years back East, will become the standard in the State as revenues dwindle.

Since the bridge has opened traffic backups have significantly dropped. What could have been a hour or more of sitting in traffic has now moved to just a few minutes. The only choke point currently is the SR 16/Interstate 5 interchange, which is currently being rebuilt.

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Photos © Ben Brooks