Based on feedback from the case study presentation at the GIC-2018 conference, the main take-aways were: • There are alternative innovative interchange designs that can be consid- ered for this location and others as applicable. • Traffic engineering options to optimize use of existing capacity should be considered in addition to capacity increasing projects. • Alternative analysis should be considered in the context of land use and all road users. • Planning and Alternative analysis need to be considered on a site-specific basis as well as on a corridor or regional level.
Presently, GTPF and its partners are focused on a second installment of the conference series planned for August 2020 (GIC-2020 - www.gtpfconference.com). The goal is to build on the momentum from GIC-2018 and to continue to contribute to Ghana’s progress in infrastructure advancements.
YOLANDA OLIVER-COMMEY, PE, PTOE is a senior engineer and project manager at Pennoni. Learn more at www.pennoni.com.
Alaskan Way Viaduct Replacement Transforming Seattle New Cliff-Side Bridge Ensures Community’s Connections for Years to Come
The Seattle underground scene has a new star: The Alaskan Way Tunnel, a nearly two-mile-long, double-decked road tunnel that is improving travel through the city’s downtown and paving the way for a revitalized public waterfront. The tunnel, which carries traffic along Washington State Route 99, replaced the Alaskan Way Viaduct (AWV) – a fixture of downtown Seattle’s Elliott Bay waterfront for more than 65 years. Between 1953 and 2019, the AWV was one of the main north-south highway cor- ridors through Seattle, until recently carrying approximately 100,000 vehicles per day. Efforts to replace the viaduct accelerated shortly after the Nisqually Earthquake, which struck the Puget Sound region in February 2001. The powerful earthquake damaged the double-decked viaduct. Repairs and strengthening kept the roadway functioning, but the 2001 earth- quake highlighted the structure’s seismic vulnerability. Later that year, the Alaskan Way Viaduct Replacement Program was established, led by the Washington State Department of Transportation (WSDOT) in partnership with the Federal Highway Administration, King County, the City of Seattle and the Port of Seattle. “WSDOT was faced with the need to replace a vulnerable and criti- cal transportation corridor within Seattle’s downtown and waterfront
Photo: Washington State Department of Transportation (WSDOT)
core,” said Paula Hammond, WSP USA transportation market leader, who prior to joining the firm was involved with the planning of the tunnel project as the Washington State transportation secretary from 2007-2013. “We had never developed a project of this magnitude—of such economic and quality of life importance to the Seattle communi- ty—and knew we had to bring our A-game through strong partnerships and community engagement to succeed.” WSP has served as general engineering consultant (GEC) to the WS- DOT for the $3.3 billion program and been involved in every aspect of the work since 2001, from planning through construction. WSP pro- vided the conceptual design and developed the technical requirements for the design-build tunnel project, prepared environmental documents and final design of some major project elements and coordinated and managed a consultant team consisting of 62 subconsultants. Tunnel Vision Using highly sophisticated virtual design and construction (VDC) and building information modeling (BIM) techniques prior to construction,
19
may 2020
csengineermag.com
Made with FlippingBook Annual report