Seattle Municipal Civic Center Master Plan
The Civic Center site lies at the south end of Seattle’s Central Business District (CBD). Located within what is regarded as the Government District, the site is bordered by the historic Pioneer Square district to the southwest and the Financial District of the CBD to the north. Because of its location at the southern edge of the CBD, the site has potential to serve as an entryway into the downtown from the south. Fourth Avenue, which bisects the site, could become a "gateway" to downtown Seattle at James Street.
The government center is adjacent to three of Seattle’s downtown’s neighborhoods - Pioneer Square, the International District, and First Hill. Because Seattle prides itself as a city of neighborhoods, the Civic Center could play an important role not only as a focal point for the entire city, but as an important center for the neighborhoods downtown as the residential population expands and the need for downtown.
James Street is the center of the government district, with the City buildings to the north and the three major County Buildings - the Jail, the Administrative Building, and the Courthouse - to the south. The adjacency of the County and City buildings offers the potential for a strong, identifiable government district with associated public spaces.
A topographic change of seventy feet between Third and Fifth Avenues enables the Civic Center to be unique among the world’s civic architecture. The topography could be utilized to create a dramatic and expressive composition of architecture and open space that would only be possible in Seattle’s downtown. The location of the site also presents an opportunity to make east-west travel easier for pedestrians by providing weather protected escalators, making the Civic Center and the dense development along Fifth Avenue more accessible from transit, from the portion of the downtown to the west, and the waterfront. The topography also provides a strong visual link between the site and Elliott Bay which could be well utilized in the design for the Civic Center.
City Hall Park is within one block of the site, on the south side of the King County Courthouse. One of the few green spaces in the downtown, City Hall Park is an underutilized resource. There is a series of small open spaces associated with buildings along Fifth Avenue and to a lesser extent, Fourth Avenue. The nearby Pioneer Square neighborhood contains a major percentage of the open space in the downtown area, including Occidental Square, Pioneer Square, and the Waterfall Gardens. The Civic Center plan should look at the context of open space in the surrounding area in order to take advantage of opportunities to activate the street network in the government center area and provide stronger links to the financial and retail districts to the north.
James Street and Cherry Street run east and west through the site. James Street originates at the historic pergola in Pioneer Square two blocks west of the site, and continues uphill past the Civic Center, running underneath Interstate-5 before connecting to the First Hill neighborhood. Traffic on James is two-way, and is an exit from northbound I-5. The view from the site down James Street includes the heart of Pioneer Square and glimpses of the water. James Street has the potential to become a stronger, more attractive link between Pioneer Square and the Government Center, and to become an improved pedestrian route to First Hill.
Cherry Street begins at First Avenue, and like James Street, runs underneath I-5 to First Hill. Cherry Street is lined by a number of historic facades for two and one half blocks east of First Avenue. These include the Broderick Building and the Alaska Building at Second and Cherry, and the ivory terra cotta facades of the Dexter Horton and the Arctic Buildings. Cherry Street is also the link between Key Tower and the two blocks now occupied by the Municipal Building and the Public Safety Building. Traffic on Cherry Street runs one way eastbound uphill, and would provides access outbound to the freeway via the express lanes and to southbound I-5. The view from the site down Cherry includes the historic facades, but terminates on First Avenue without continuing the water.
The north-south streets - Third, Fourth and Fifth Avenues - have a more gentle topography rising from south to north. These avenues all accommodate heavy traffic, including numerous Metro bus routes. Traffic on Third Avenue is two-way, while Fourth and Fifth Avenues form a one-way couplet, with northbound traffic on Fourth and southbound traffic on Fifth. Fifth Avenue parallels I-5, and a substantial portion of downtown traffic uses Fifth Avenue to access the freeway entrances. Entries to the express lanes out of the city are located at the base of Key Tower on the northwest and the southwest corners. Contraflow bus traffic uses Fifth Avenue to enter the express lanes at the corner of Fifth and Cherry.
Pedestrians in downtown Seattle tend to favor the north-south routes because of the easier grades. There is substantial pedestrian trafficon all three Avenues, though less than in the retail portion of the CBD to the north. Three high rise buildings, including Key Tower, are joined below grade by a system of tunnels with shops and restaurants.
A major advantage of the site is the presence of a transit entry at the corner of Third and James. The design of the Civic Center should take maximum advantage of the accessibility of the site, and should also support the use of transit by making pedestrian access up the hill easier and fully accessible. The transit tunnel is currently used by Metro buses but will become the light rail route for Sound Transit.
All three north-south avenues are heavily used by Metro buses. Fifth Avenue has major bus stops on both the east and west sides of the street for express buses. Bus traffic is likely to increase when buses are relocated from the tunnel back to the street. People waiting for the buses should be accommodated within the Civic Center design in an ample, comfortable and weatherproof waiting area. The presence of these people should also be taken advantage of to enliven the Civic Center area.
There is currently parking below both the Municipal Building and the Public Safety Building. Key Tower is served by an on-site 650 car parking garage.
The building height and will have an effect on the amount of sunlight the site will receive. Because the Civic Center is primarily about public space, maximizing light and sunshine is a high priority, particularly given the climate of Seattle.
Arranging the building masses along the north and east edge of the two block site optimizes the amount of sun in the open space. The following solar access studies graphically depict sun exposure through the course of the year. During the summer months, the site is bathed in sunlight for the majority of the day. By 6:00 pm, shadows cast by the buildings along the north edge and adjacent taller buildings place the open space in shade.
A September morning finds the open space in shade. As the sun moves west the eastern portion of the open space becomes washed in sunlight. By late afternoon, 3:00 pm, the space is in total sunlight. As the diagram indicates, by 6:00 pm the majority of the site is in shade.
During the winter months, the surrounding buildings cast longer shadow because of lower sun angles. At noon pockets of sunlight penetrate the east and west ends of the open space. The greatest sun exposure occurs in the late afternoon at around 3:00 pm.
During the design phase solar orientation should carefully be studied so as to maximize sun exposure throughout the year. Wind will also have an effect on the character and comfort of the open space. Wind tunnel tests and analysis is advised during the design phase.
The civic center site lies within two zoning designations. The Municipal Building site is in the Downtown Office Core I, (DOC-I). The Public Safety Building site is in the Downtown Office Core II, (DOC-II). The diagram on page 25 shows height limits and setback requirements at the various heights of the building envelope. The map indicates the Public Benefit Features (PBF) and the street level Pedestrian Classifications that address each block.
The following is an initial analysis of advantages and disadvantages of several alternatives for providing a pedestrian connection between the City Hall (Key Bank Building) and the proposed Civic Center. This connection is important because the City Executive Offices are expected to be located in the Civic Center and many of the Departmental staff will be located in either the Law and Justice Building or City Hall. Under existing conditions, this distribution of buildings and functional relationships would require staff to cross the street at grade at the signalized intersection of 5th Avenue at Cherry Street. The purpose of this analysis is intended to address the opportunities and constraints associated with several pedestrian connection options.
Four pedestrian crossing alternatives were examined and include the following: 1) at-grade crossing with the signals; 2) at-grade crossing diagonally across the intersection; 3) above grade crossing (sky bridge); and 4) below grade crossing (tunnel). This analysis is presented in a summary matrix form that identifies the strengths and weaknesses associated with each as well as additional investigation that could be performed to validate the initial findings associated with this comparative analysis.
The analysis is based on a physical inventory of conditions, available traffic volume and traffic signal timing characteristics, utility maps, and channelization drawings.
The Fifth Avenue and Cherry Street are one-way streets that carry 4-lanes of traffic southbound and 3-lanes of traffic eastbound respectively. On Fifth Avenue a contra-flow transit lane south of Cherry Street serving the peak period reversible ramp matches a southbound left turn lane north of Cherry Street. On Cherry Street at Fifth Avenue, the parking lane (for police vehicles only) transitions to an exclusive right turn lane. The traditional intersection pattern is modified by a fifth intersection 2-lane reversible ramp that serves Metro Transit and High Occupancy Vehicles (HOVs) that runs diagonally under the Key Bank Building to across the I-5 express lanes.
The intersection is controlled by a three-phase traffic signal that is interconnected as part of the downtown signal system. The downtown signal system permits the one-way streets and the traffic signals to operate efficiently. Pedestrians cross the intersection with the traffic signal north south with Fifth Avenue traffic and east west with the Cherry Street traffic.
PM peak hour traffic volumes are the highest of the day. Approach PM peak hour volumes at this intersection are about 1300 vehicles per hour (vph) eastbound on Cherry Street, 1180 vph southbound on Fifth Avenue, and 55 vph on the contra-flow lane of Fifth Avenue.
A wide variety of underground utilities run along both 5th Avenue and Cherry Street. These including storm sewer, pressure sewer, clay tile drain lines, water (24"), gas, and fiber optics lines. These utilities are most highly concentrated at intersection itself and on the north, east and west legs of the intersection.