Interested in design options for the new Sellwood Bridge? The architect for the project, Ricardo Rabines, will give a free lecture on Monday, August 30 at 3pm at the American Institute of Architect’s Center For Architecture at 403 NW 11th Ave.
But don't expect Rabines to be able to answer the larger question surrounding this bridge: how we balance the needs of transit with those of neighborhoods.
The Sellwood Bridge project is a planning effort to replace the 85-year old Willamette River crossing in Southeast Portland. A preferred alternative to replace the bridge was approved at the local level in 2009. The project is currently in a preliminary public process phase that will determine the type of bridge structure to be built. Multnomah County expects to select the structure type for the new bridge later this year. Construction should begin in 2012.
Ricardo Rabines is a co-founder of Safdie Rabines Architects in San Diego. His award-winning work includes designs for bridges in San Diego (such as the Scripps Crossing pictured below) and Des Moines, Iowa. "Ricardo likes to say that each bridge he works on has its own personality that relates to its site and community needs," Multnomah County spokesman Mike Pullen told me.
Currently involved in a variety of projects around the country, some of Safdie Rabine’s recent commissions include the South Campus Student Center at UCLA, the Structural and Materials Engineering Building at UCSD, and the El Centro Family Courthouse. Projects recently completed include The Robert Paine Scripps Forum for Science, Society & the Environment at the Scripps Institution of Oceanography and Baldwin Hills Scenic Overlook State Park in Los Angeles. Their work also consists of several vehicular and pedestrian bridges such as the Harbor Drive Pedestrian Bridge in downtown San Diego.
The preferred Sellwood Bridge alternative selected through public input is a new two-lane bridge with two sidewalks, two shoulders/bike lanes and a traffic signal at the west end connection with Highway 43. Any new bridge must also the following criteria: a cross-section without a raised center median, a total cost of less than $330 million, no long term traffic closures, a construction footprint that minimizes impacts to adjacent businesses and residences, and room to accommodate a future streetcar.
There are eleven bridge types currently under consideration that are possible with new construction techniques and the alignment chosen in the preferred alternative. The alignment will be approximately 15 feet south of the existing Tacoma Street centerline to allow for continuous traffic flow at the crossing throughout construction. The possible bridge types include deck structures (no superstructure above the deck) and thru structures (support structure above the deck).
Although the renderings included in this post only show one of the bridge design option, the deck arch, I was surprised at how similar it looked to the existing Sellwood bridge. I'm no expert on this, admittedly, but if we build a bridge that looks and performs like the old bridge, why aren't we just fixing the old one?
I was shocked to learn that the preferred alternative here is a two-lane bridge. This is the only bridge over the Willamette for miles in either direction, and we want to keep allowing only one car in each direction? What century is this?
Naturally I say this with the understanding that accommodating too many car lanes can lead to sprawl. And we have to consider the streets that feed onto and off of the bridge. In the case Southeast Tacoma Street, on the east side of the Sellwood Bridge, it is indeed just one lane in each direction. But on the other side, the bridge is fed by multi-lane Macadam Avenue and Highway 43. Thousand of commuters use this bridge every day to get back and forth between Clackamas County, Southwest Portland and Lake Oswego. Is tearing down one bridge with a single lane in each direction and building another bridge with a single lane in each direction really the best investment we can make for the future with this infrastructure?
It seems to me the Sellwood Bridge has an inherent identity crisis that has never been fully resolved by the bridge design process. For the west side, this is an important connection affecting major traffic arterials. It's about moving cars. For the east side, it's more about protecting the modestly scaled local neigbhorhood of homes and businesses. We don't want multiple lanes of cars zooming dangerously fast past the antique stores of Sellwood.
I'm not saying one side of the bridge occupies moral or functional high ground over the other. But if some are expecting an improved commuter bridge with reduced traffic and others are expecting a modest replacement of a modest neighborhood span wherein minimized impact is of greater importance than maximized movement, how can we possibly design a bridge that will satisfy?
It's not designer Ricardo Rabines' job to settle the Sellwood Bridge's inherent conflict about what it should be. He's here to present different off-the-shelf bridge types and work with us to select one and then make it fit our local context. But it strikes me that the Sellwood Bridge is more than infrastructure we have to replace. It's part of a larger conundrum we haven't solved: how to balance moving traffic with preserving neighborhoods.
[Update, 8/30/10] A couple days after initially posting this article, I'd like to pass on comments from Mike Pullen of Multnomah County on the bridge. Perhaps the single lane in each direction is the only way to go:
"Traffic studies showed that a four lane bridge would not improve congestion, due to the two-lane layout of Tacoma St. and the traffic signals on that street. Brian is correct that more than two lanes are needed at the west end of the bridge, where traffic turns north to Portland or south to Lake Oswego. The bridge will have four lanes at the west end to increase the flow of traffic through a signalized intersection there. The signal will be adjusted to give more green time for traffic in the dominant direction, depending on the time of day. The best improvement in congestion will likely be for Portland to Lake Oswego traffic, which will pass under the new bridge. That traffic should be able to avoid the afternoon congestion at the bridge."