by Ron Swaren
Please note I am not referring to a copy of I-205 placed on Portland’s west side or any Westside Bypass Freeway. However, when the Columbia River Crossing task force eliminated competitive proposals the central reasoning seemed to be that these were “not in the (I-5) bridge influence area.”
But aside from tearing down the I-5 bridges, wouldn’t we want any supplemental structure to be outside the “influence area?” I’m not talking about Idaho, simply at other points within the Metropolitan area. And there is no good reason to tear those existing bridges down.
I have been through a number of seismic upgrading projects, including the I-5 Lake Washington Canal Bridge in Seattle. With the right connections we should be able to get the respected PEER Lab (Pacific Earthquake Engineering Research) at Berkeley, CA to draft some proposals. A common engineering technique, applicable to buildings and bridges, is to “isolate” the structure from the foundation. Sophisticated bearings that absorbed shock or harmlessly wobble with larger earth movements, combined with designs where larger segments of the structure can bend or twist a bit, reduce the ground energy that transmits to the structure. The larger concept is “dampening,” i.e. reducing movement, by a series of shock absorbing techniques. With the I-5 bridges, a main concern is that the 700 ton counterweights could begin swaying in a prolonged event and damage the structure. So their movement needs to be dampened, not passed along accentuating ground movements.
So first of all, can we agree that there are, or will be shortly, engineering concepts that will solve the I-5 bridges’ vulnerabilities? See the homepage of the PEER lab at: http://peer.berkeley.edu/
This would eliminate the argument that they need complete replacement. And I don’t believe rehab costs would be in the $250 million range. A highrise building, which also incorporates seismic protections plus a number of other systems is generally under $100 million. And according to the latest US Geological Survey report Portland is not in as nearly a dangerous area for earthquakes as is the southern Oregon coast.
Back in 1980 the I-5 route in North Portland was beginning to experience slower travel times. but the real onslaught came with the concentration of thousands of new jobs in the high tech corridor between Beaverton and Hillsboro, the Silicon Forest. Today, from a good vantage point, you can even see that late afternoon traffic now comes more from the Fremont Bridge and western Portland, than through northbound on the I-5. Unlike the eastern suburbs no interstate route has ever been built, so all of the traffic from Washington headed to the westside must use I-5, or possibly I-205 if it is bound further south.
The most common strategy is to circumvent a major city center with a Ring Road. so that large portions of traffic are diverted away from the center. On our east side we have I-205 and in the SW we do have a functional route, Hwy. 217. It is in the NW where there is no completion of a ring road. I have proposed the Western Arterial Hwy. connecting from US 26 at West Union to Hwy 500 and NE 39th street in Vancouver. This could simply be a four lane highway. The ROW already largely exists. Other routes, such as NW Cornelius Pass Rd. could augment this route, and placing it close-in on the Vancouver side a number of east-west thoroughfares could tie in. See some of my previous articles for more details.
Last year Clark Co. voters approved an advisory resolution for a third Columbia River crossing at 192nd Ave. I think the major drawback of this is that the areas served by this proposed bridge are rather small, in comparison with the Beaverton-Hillsboro-Forest Grove-Banks-Tigard area. Get my picture? The 192nd Bridge would facilitate future development (another area for argument) whereas the Silicon Forest problems are already here. I suspect also that much of the motivation for a 192nd Avenue bridge comes from the thought of being easier to get to Oregon for E. Clark Co. residents wanting to save sales taxes, and perhaps not having as many local commercial opportunities. This proposal is for a rather long bridge, of 10,000 feet, whereas a distance one-fourth of that is available upstream.
A Western Arterial highway without the fancy light rail features tends to get a yawn from Portland’s anti highway crowd. But for those wanting to reduce travel times by all modes it has a lot of appeal. To get from downtown Vancouver to West Union Junction via I-5 and US 26 is now a 20 mile trip. The return trip can take a horribly long time, as congestion on both routes skyrockets. A Western Arterial route would be 14 miles or less. If a Western Arterial route can relieve enough traffic from I-5 the level should return to tolerable. Right now it is beyond the tipping point, and dramatically slow. But when functioning at normal speeds bus transit is less impeded. A shortcut will benefit all those who use it.
For solving the traffic issues from west side metropolitan growth the other options just don’t pencil out. A Bypass Freeway would be prohibitively expensive. Light rail through Clark County would also be very expensive (costs are now around $200 million per mile) and likely would be underused. A 192nd Ave. Bridge is ten miles away from I-5 and would have little impact. Apart from the political reasons, which boil down to a “if it isn’t my idea, I don’t want it” provincialism, the Western Arterial route from a financial standpoint would provide the most bang for the buck, to solving I-5 problems. As a previous article pointed out with the construction of new bridges we can probably also incorporate some sophisticated energy saving features to benefit public transit such as electrical turbines powered by river current.
Ron is a resident of the Portland area, has been involved in transportation issues and participates in the UN World Urban Forum. As a commercial journeyman carpenter he has built some of the major structures in the Portland area and believes that costs on public works need to be dramatically reduced.