Chapter 1. Purpose and Need

Transcription

1 Chapter 1. Purpose and Need

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3 Chapter 1. Purpose and Need 1.1 Why are we considering the Sellwood Bridge project? After 80 years, the Sellwood Bridge has reached the end of its useful service life. The purpose of the Sellwood Bridge project is to rehabilitate or replace the bridge to make it structurally safe. Additionally, the project would improve connections, operations, and safety for vehicles, bicycles, and pedestrians. The bridge carries more than 30,000 vehicles per day, making it Oregon s busiest two-lane bridge. Congested conditions and slow travel speeds occur because the travel demand served by the Sellwood Bridge exceeds the available capacity for several hours each day, primarily during the morning and evening peak hours. Multnomah County, which owns and maintains the bridge, has been working with the Project Purpose and Need Project Purpose To rehabilitate or replace the Sellwood Bridge within its existing east-west corridor to provide a structurally safe bridge and connections that accommodate multi-modal mobility needs Project Need The need for the proposed action is as follows: Inadequate structural integrity Substandard and unsafe roadway design Substandard pedestrian and bicycle facilities across the river Existing and future travel demands exceed available capacity Existing Sellwood Bridge. Oregon Department of Transportation (ODOT), the City of Portland, and Metro (the Portland area metropolitan planning organization) to find a solution. 1.2 Where is the project located? The bridge crosses the Willamette River in Portland, Oregon. It connects Oregon 43 (OR 43) on the west side of the river with Oregon 99E (OR 99E) by way of SE Tacoma Street on the east side of the river. OR 43 runs north-south between the cities of Portland and Oregon City, traveling through Lake Oswego and West Linn. OR 43 is referred to as SW Macadam Avenue within the city limits of Portland. On the east side of the river, the bridge transitions into SE Tacoma Street. At its east end, SE Tacoma Street connects with OR 99E (SE McLoughlin Boulevard). The next closest crossings over the Willamette River are about 2.5 miles north at the Ross Island Bridge and about 8 miles south at the Interstate 205 (I-205) Abernathy Bridge. The Se llwo o d B ri dge Pro j e c t F i nal En vi ro n me nt al I mp ac t Stat e me nt 1-1

4 What is t he p ro j e c t s e t t ing? Sellwood Bridge links the Sellwood, Westmoreland, and Milwaukie areas with OR 43 and southwest Portland, downtown Portland, and Lake Oswego. Figure 1.2-1, Project Vicinity, shows the location of the project. Figure 1.2-2, Existing Conditions, shows existing land uses near the bridge. 1.3 What is the project setting? The bridge is located in an urban setting with mixed residential, commercial, recreational, and historical uses. Strips of land adjacent to the Willamette River near the bridge, particularly on the west side, are natural and undeveloped, though with significant recreational use. On the east bank, the Sellwood Bridge is a gateway to the Sellwood-Moreland neighborhood. Many of the properties on the east bank along the river are condominiums, apartments, or commercial buildings. The Springwater Corridor Trail passes below the bridge, as does the Willamette Greenway Trail (East Bank). Sellwood Riverfront Park, Oaks Pioneer Park, Oaks Amusement Park, and the Springwater Corridor Trail are accessed from the intersection of SE Tacoma Street and SE 6th Avenue on the east bridge approach. On the west bank, the bridge approach crosses over Powers Marine Park, a linear river park, and ends in an interchange with OR 43. The interchange is adjacent to the east entrance to River View Cemetery, a large pioneer and working cemetery that is on the hillside above the highway. The historic Superintendent s House, which is associated with the cemetery and currently functions as a funeral home, is accessed from OR 43, just south of the OR 43 intersection with the bridge. Staff Jennings, a former commercial boating business (closed in March 2010), is located along the west side of the river between the interchange and the river, north of the bridge and Powers Marine Park. To the north of the Staff Jennings property is Willamette Moorage Park. The Willamette Shoreline Trolley track, a publicly owned right-of-way, also runs the length of the project north and south between OR 43 and both Powers Marine Park and Willamette Moorage Park, as does the Willamette Greenway Trail (West Bank). 1.4 What is the history of the project? Built in 1925 The bridge was constructed in 1925 to replace the Spokane Street Ferry, which shuttled passengers across the Willamette River between Sellwood and southwest Portland. The bridge designer was Gustav Lindenthal, a noted bridge engineer of the time. Like the Ross Island and Burnside bridges in Portland, the Sellwood Bridge was built with funds from a $4.5 million local bond measure. In response to public outcry at budget overruns on the Burnside Bridge, the Sellwood Bridge design was scaled back to minimize cost. With a construction cost of just $541,000, the scaled-down design resulted in a number of limitations. The bridge is extremely narrow two lanes, no shoulders or median, and one narrow sidewalk that must accommodate light poles, pedestrians, and bicyclists. Because it was not designed for the additional weight of streetcars, the bridge cannot withstand as much weight as the other Willamette River crossings in Portland, such as the Hawthorne and Steel bridges. The Sellwood Bridge was constructed in 1925 to replace the Spokane Street Ferry. 1-2 Se ll wo o d B rid ge P ro j e c t F in al En viro n me nt a l I mp ac t Stat e me nt

5 What is t he history o f t he p ro j e c t? FIGURE Project Vicinity FIGURE Existing Conditions Se llwo o d B ri dge Pro j e c t F i nal En vi ro n me nt al I mp ac t Stat e me nt 1-3

6 What is t he history o f t he p ro j e c t? Oregon s First-Ever Four- Span, Continuous-truss Bridge The Sellwood Bridge is the only four-span, continuous-truss highway bridge in Oregon, and possibly in the nation. (A continuous-truss requires fewer parts and costs less than other bridge types to construct. At the time of the Sellwood Bridge s construction, the computational technique for this design was newly developed.) As one of Portland s first fixed-span bridges across the Willamette River, the bridge was high enough to avoid the need to open for river traffic. It was also Portland s first Willamette River bridge without trolley tracks Topographic Challenges In addition to these design limitations, the bridge also has topographical challenges. The west end of the bridge was constructed on fill material and it is located in a geologically unstable area. The hillside above the bridge is slowly sliding toward the Willamette River, exerting pressure on the west end of the bridge. In the late 1950s, the hillside slid several feet toward the bridge. As a result, a 3-foot segment of the bridge deck had to be removed and foundations were reinforced. The west-side interchange with OR 43 was completely rebuilt in Since then, ground movement has caused the west-side approach girders to crack Recent Safety Measures Multnomah County continues to take steps to prolong the safe use of the bridge until a longterm solution is identified. In June 2003, cracks in both the east and west concrete approaches were discovered and restrained with external steel clamps. In June 2004, the weight limit for vehicles traveling across the bridge was reduced from 32 tons to 10 tons. This weight limit caused the diversion of 94 daily TriMet bus trips (a loaded bus weighs about 19 tons). The weight limit is still in effect. In 2005, an engineering study recommended short-term safety improvements for the bridge; cracks in the girders and columns were injected with epoxy in The County is inspecting the bridge every 3 months to monitor the cracks and the slope on the west side of the bridge to ensure continued safe use of the bridge Planning Framework 1999 Metro Study In May 1999, Metro made recommendations for the South Willamette River Crossing Study, which included the Sellwood Bridge. The study, initiated by Metro s Joint Policy Advisory Committee on Transportation, identified needed improvements for cars, transit, bikes, and pedestrian traffic crossing the Willamette River between southeast Portland and Oregon City. One of the study s recommendations was to preserve the existing Sellwood Bridge, or replace it as a two-lane bridge with better service for bicyclists and pedestrians. Regional Transportation Plan Metro s 2004 Regional Transportation Plan (RTP) is a 20-year blueprint for the Portland metropolitan region s transportation system and an adopted Functional Plan integrated into the Regional Framework Plan. The plan addresses the movement of people and goods in and through the region. The plan identifies the region s transportation needs, including the need to limit the amount of congestion experienced and to maintain access for national and international freight to reach its destination with limited delays. The Sellwood Bridge project is listed as Project 1012 on the 2004 RTP financially constrained project list for the RTP program years 2004 to The RTP is currently being updated, and its adoption is anticipated in June of Future project phases, including the purchase of right-ofway, is expected to be included in the list of financially constrained projects in the updated RTP. Right-of-way purchase must be included in the financially constrained RTP before the Federal Highway Administration (FHWA) can issue a 1-4 Se ll wo o d B rid ge P ro j e c t F in al En viro n me nt a l I mp ac t Stat e me nt

7 Record of Decision on the Sellwood Bridge project. Tacoma Main Street Plan Completed in 2001, the City of Portland s Tacoma Main Street Plan was developed to implement the vision of a multi-modal, neighborhood-oriented street in the Sellwood- Moreland neighborhood. A basic assumption carried into the planning process (according to recommendations from the South Willamette River Crossing Study [Metro, 1999]) was that providing adequate regional traffic capacity in the Sellwood Bridge/SE Tacoma Street travelshed is not the responsibility of SE Tacoma Street. The plan supports regional efforts to carry out the recommendations of the South Willamette River Crossing Study that reduce travel demand on the Sellwood Bridge. Action items to meet this recommendation include mitigating traffic growth on SE Tacoma Street, increasing transit services, increasing motor vehicle capacity on appropriate regional facilities in order to direct traffic away from areas of conflict with land use goals, and supporting improvements to the west end of the Sellwood Bridge that mitigate congestion impacts. 1.5 What is the purpose of the project? The purpose of the project, as approved by the project s Policy Advisory Group, is to rehabilitate or replace the Sellwood Bridge within its existing east-west corridor to provide a structurally safe bridge and connections that accommodate multi-modal mobility needs. Project Purpose, Need, and Goals What is t he p u rpo s e o f t he pro j e c t? 1.6 Why is the project needed? The following four major issues define the need for the Sellwood Bridge project: Project Purpose (Section 1.5) Defines the transportation problem to be solved, but does not identify a solution, and allows for consideration of multiple modes and alternatives. Project Need (Section 1.6) Establishes evidence that the transportation problem exists. Project Goals (Section 1.7) Defines broad vision statements intended to influence the character of the project solution. Inadequate structural integrity to safely accommodate various vehicle types (including transit vehicles, trucks, and emergency vehicles) and to withstand moderate seismic events Substandard and unsafe roadway design Substandard pedestrian and bicycle facilities across the river Existing and future travel demands between origins and destinations served by the Sellwood Bridge exceed available capacity The following subsections provide further descriptions of these issues. The yellow line indicates a sag in the southern bridge railing. Se llwo o d B ri dge Pro j e c t F i nal En vi ro n me nt al I mp ac t Stat e me nt 1-5

8 Why is t he p ro j e c t ne e de d? Inadequate Structural Integrity The bridge has inadequate structural integrity to safely accommodate various types of heavy vehicles (including transit vehicles, trucks, and emergency vehicles) and to withstand moderate seismic events. The bridge continues to deteriorate and cannot adequately accommodate today s traffic needs because of its structural condition. Load restrictions have eliminated bus service, restricted freight loads, and prohibited large emergency vehicles from using the bridge. The bridge does not meet current seismic standards. The bridge is no longer adequate to sufficiently accommodate traffic because of its structural and geometric deficiencies. Its sufficiency rating (a measure based on bridge inspection reports that indicates a bridge s ability to provide service) is only 2 on a scale of 0 to 100. The sufficiency rating measures both the physical condition of a bridge and the ability of the bridge to perform operationally. Side of the bridge, which shows that concrete has fallen off the bridge. The bridge s lightweight deck system is inadequate to handle current vehicular demands. Concrete is falling off the bridge because the reinforcing steel is corroded and expansion joints are weakening. The existing lead-based paint coating has largely failed and widespread corrosion is attacking the steel truss. The bridge was opened to traffic in However, the steel girders of the bridge approaches are actually more than 100 years old because steel girders from the Burnside Bridge (circa 1894) were reused on this bridge. Earth movements caused the development of cracks in the west approach concrete girders. Vehicle loads were restricted to a maximum of 32 tons in 1985 after calculations showed that higher weights would overstress critical bridge elements. Further weight restrictions were imposed in 2004, when large cracks were discovered in the concrete girders. Vehicle weight was limited to 10 tons and buses and large emergency vehicles and trucks were prohibited from using the bridge. Portland s Freight Master Plan (2006) designates the bridge as a Truck Access Street in recognition of its service as an access and circulation route for the delivery of goods and services to neighborhood-serving commercial and employment land uses. This includes truck trips between Sellwood, Westmoreland, and Milwaukie on the east side of the Willamette River and the southwest Portland area on the west side, via OR 43. However, because of current load restrictions and the physical geometry of the west-side interchange, large trucks must avoid the bridge, thereby substantially impeding freight movement between these areas. This out-of-direction travel for businesses located in the commercial districts on both sides of the river has resulted in increased freight costs and delays. Freight mobility and reliability, currently affected by load limits on the bridge, will be further impacted as travel demands continue to rise. 1-6 Se ll wo o d B rid ge P ro j e c t F in al En viro n me nt a l I mp ac t Stat e me nt

9 Why is t he p ro j e c t ne e de d? The existing lead-based paint coating has largely failed and widespread corrosion is attacking the steel truss. Transit service has been discontinued across the bridge because of the structural deficiencies. Before the weight restriction was imposed in 2004, bus usage across the bridge was substantial. (SE Tacoma Street is a Major Transit Street in the City of Portland s Transportation System Plan [updated in 2007].) Bus routes that previously crossed the bridge served many travel markets, including those between the Sellwood, Westmoreland, and Milwaukie areas and southwest Portland and the city center. Since the weight restriction, the bus routes have been rerouted, making use of public transportation unattractive between key markets. Transit use in the bridge corridor (which is expected to rise substantially by 2035) and increased traffic levels could affect the reliability and mobility of public transportation service. Finally, the bridge is located in a seismically active zone, does not meet current seismic standards, and is vulnerable to failure in the event of an earthquake. The interchange of the bridge and OR 43 has many substandard features, including horizontal and vertical alignments that limit motorist sight distance and prohibit the ability of longer trucks to turn safely. Ramp connections also do not provide sufficient vertical clearances (16.25 feet on the southbound loop ramp from the Sellwood Bridge to OR 43 southbound when the ODOT minimum is 17 feet), sight distances, or shoulders Substandard Pedestrian and Bicycle Facilities across the River The bridge s only sidewalk, on the structure s north side, is just 4 feet 3 inches wide. This leaves only a 3-foot-wide passage for two-way traffic next to each of its 22 light poles. The sidewalk width is not safe for bicyclists and pedestrians, and the sidewalk cannot accommodate some disabled users. The existing sidewalk and connections at either end of the bridge do not meet Americans with Disabilities Act (ADA) requirements. There is no sidewalk on the south side of the bridge. The bridge does not provide designated bicycle facilities. Some bicyclists try to use the sidewalk; others intermingle with traffic. The bridge could provide bicyclists and pedestrians with a critical link between the west and east sides of the The bridge s sidewalk width is not safe for bicyclists and pedestrians Substandard and Unsafe Roadway Design The bridge has two 12-foot-wide lanes with no shoulders to provide access for emergency vehicles, accommodate vehicular breakdowns, or facilitate maintenance. In addition, the bridge s vertical curve limits motorist sight distance. Se llwo o d B ri dge Pro j e c t F i nal En vi ro n me nt al I mp ac t Stat e me nt 1-7

10 What a re t he go als o f t he p ro j e c t? Willamette River and with established shared-use paths. However, the bridge s connections with shared-use paths are deficient, unsafe, and often avoided. There are no sidewalks, crosswalks, or bicycle lanes on OR 43 in the bridge interchange. Pedestrian and bicyclist connections between the highway and the bridge are circuitous, unpaved, and, in some areas, force users to mix with vehicle traffic. Most of these facilities do not comply with ADA guidelines. In addition, the bridge s connection to the Willamette Greenway Trail (West Bank) is narrow; has deficient horizontal curves and limited sight distances; and does not meet ADA standards Travel Demands Exceed Available Capacity Capacity is defined as the number of vehicles over a given time period that can be served by a section of roadway. Capacity is a function of the facility s lane capacity, travel speeds, and operations of intersections, as well as those of upstream and downstream facilities. The existing and future travel demands served by the Sellwood Bridge exceed the bridge s available capacity as well as the capacity of its interchange with OR 43. The bridge provides a direct connection across the Willamette River for several key travel origins and destinations. Travel demands are expected to increase in the future, leading to decreased accessibility for motorized vehicles. The bridge s closest alternative crossings over the Willamette River are about 2.5 miles north at the Ross Island Bridge and about 8 miles south at the I-205 Abernathy Bridge. Travel demands at the bridge and west-side interchange exceed the available capacity for several hours each day, resulting in congested conditions, slow travel speeds, and travel delays. During peak conditions, particularly during the afternoon, vehicles waiting to get on the bridge and go eastbound often extend onto OR 43 beyond the SW Taylors Ferry Road intersection. Daily traffic demand will increase substantially in the future, leading to increased durations of congestion along approach roadways, including both directions of OR 43, SW Taylors Ferry Road, and SE Tacoma Street. Increased congestion levels will affect emergency service accessibility, transit service, freight movements, and general vehicular traffic. The two key facilities affecting Sellwood Bridge operations are the OR 43 interchange and SE Tacoma Street. Both create bottlenecks that increased capacity or operational improvements on the bridge itself cannot relieve. For example, on the east side, SE Tacoma Street is controlled by a single through lane in each direction and the capacity-constraining traffic signals at SE 13th and SE 17th avenues. It is the intention of the City of Portland s land use and transportation plans, as expressed in the adopted Tacoma Main Street Plan (2001), that the Sellwood area maintain SE Tacoma Street as a two-lane facility, with a turning lane, but improve the operations of the signalized intersections on SE Tacoma Street to improve the operating capacity of the corridor. On OR 43, the slow speed on-ramps to the bridge from OR 43 both merge into a single lane on the bridge, leading to congestion on OR 43. This interchange is not addressed in a plan except as part of the bridge project. 1.7 What are the goals of the project? Through a public involvement process, a diverse group of concerned stakeholders defined the goals for the project that addressed the assessed needs and defined the criteria for a successful solution. A Community Task Force (comprised of residents and business owners in adjacent neighborhoods; bicycle and pedestrian users; freight and transit advocates; commuters; citywide business and community interests; river users; and historic resource, aesthetic, and natural resource protection supporters) 1-8 Se ll wo o d B rid ge P ro j e c t F in al En viro n me nt a l I mp ac t Stat e me nt

11 What a re m ini m um re q ui re me nt s fo r me e t i ng pro j e c t p ur po s e an d ne e d? articulated the perspectives of their constituencies during this process. Improving the safety of the bridge is the primary goal. An important secondary goal is to balance environmental and transportation values over the long-term while meeting the purpose and need for the proposed action. The project goals are further defined as follows: Mass Transit. Improve mass transit circulation, capacity, connectivity, and local access to and across the bridge. Seismic. Provide a solution that can resist moderate earthquakes. The project goals are addressed in the analysis of impacts, the mitigation for impacts, and the project design. Aesthetics. Ensure an aesthetically pleasing solution that enhances visual quality of the bridge, on the bridge, and from the communities on both sides of the river. Bike and Pedestrian. Improve pedestrian and bicycle connectivity, mobility, and safety to and across the Sellwood Bridge. Community Quality of Life. Protect and preserve the existing quality of life of the neighborhoods in the Sellwood Bridge influence area on both sides of the Willamette River. Automobiles, Freight, and Emergency Vehicles. Improve freight and commuter mobility and safety. Minimize bottlenecks for freight, automobiles, and emergency services. Construction. Minimize construction impacts and construction risks. Cost and Economic Impacts. Design, build, and maintain a cost-effective project. Natural Environment. Preserve or improve the natural environment. Material Resources. Use material resources as efficiently as possible. 1.8 What are minimum requirements for meeting project purpose and need? Once the goals for the project were established, decision-makers defined a set of threshold criteria to serve as minimum requirements for reasonable project alternatives. Chapter 2 summarizes the threshold criteria. These threshold criteria (design standards and performance measures) have been used throughout the alternative development and screening process to ensure that the project needs as expressed in the project goals are met. (See Appendix D for a list of supporting technical documentation.) Project Stakeholders A diverse group of concerned stakeholders developed the goals for the project. These stakeholders include the project team, project decision-making bodies (described in Chapter 5), various interest groups, and the public who raised issues throughout the public involvement process. Se llwo o d B ri dge Pro j e c t F i nal En vi ro n me nt al I mp ac t Stat e me nt 1-9

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