The consultant team and advisory committee used the Technical and Regulatory Considerations listed below and the Objectives (Objectives tab) as a framework for determining the feasibility of the various alignment and landing options.
|Mayor's Advisory Committee discussing options.|
Technical and Regulatory Considerations
- Minimum bridge/trail widths
- Horizontal geometry constraints (including minimum radii for curves) and allowable design speeds for bicycles
- Maximum allowable vertical grades and rates of curvature for both bridge structures and for access
- Railroad clearance parameters
- Roadway clearance parameters
- Emergency access requirements
- Maintenance access requirements
- Minimum lighting requirements
- Requirements for storm water detention and water quality
- BNSF permit support requirements and timeline
- Identify constructability issues and parameters associated with railway
- Utility clearance requirements
- Structural loading conditions
- Allowable structural deflections and vibrations
Option B- eliminated
|Option B, eliminated|
This alignment connected to Sherman on the south side, then continued towards Grant along the sloped area between the railroad tracks and the private property boundary and crossed over to campus node similar to Option A. This alignment was eliminated when it was found that the area of land designated for the pathway was owned by BNSF, who has plans for future track expansion within this area.
Option D- eliminated
This alignment connected to Sherman on the south side and immediately crossed BNSF and landed at the intersection of Martin Luther King Jr Way (MLK) and the future north Sherman.
|Option D, eliminated|
Two sub concepts were researched related to this options: D2 considered a ramp traveling north along the future
extension along the east side of the future roadway. D3 considered the ramp traveling north along Sherman and east along the MLK corridor. Both sub concepts failed because they couldn’t overcome the disadvantage of the large area needed for the ramps and the long distance needed to be traveled for those that could not use a more direct stairway system. Both sub concepts also were eliminated because they would take pedestrians away from locations providing multiple choices for pedestrians and the fact that that both sub concepts would create a visual and physical barrier. Sherman
Option E, moved forward as Option 2
This alignment connects with Sherman and then travels at an angle directly to the campus node defined by the intersection of pathways from the campus central spine or mall and Main Street. This is moving forward as Option 2.
The advantage of this alignment is the intersection of Sherman and Sprague is signalized thus providing a safe crossing for pedestrians. In addition, Sprague is also a through street traveling south to the medical district and connecting with the overall non-motorized plan of the City.
|Option E moved forward as Option 2|
Vertical clearances requirements above the City roadways and transit corridors are less than those required for BNSF; consequently, once the bridge crosses the BNSF right-of-way, the bridge height can begin to come down. Once the bridge reaches the Riverpoint campus, the bridge height is approximately 16 feet rather than the 26 feet in other options. In turn, this reduces the ADA ramp length by approximately 140 feet for a total length of approximately 230 feet. The shorter ramp requires less land area to construct and can fit within the parameters of the campus master plan.