Elevated Structure Alternative. The AWV project team combined elements of the Aerial and Rebuild Alternatives evaluated in the Draft EIS into the new Elevated Structure Alternative described and evaluated in the Supplemental Draft EIS and this memorandum. The main features of the Elevated Structure Alternative are described within each geographic section of the project area.
Elevated Structure Alternative. The Elevated Structure Alternative includes rebuilding the viaduct in place with dimensions similar to the Aerial Alternative discussed in the Draft EIS. As compared to the Aerial Alternative, the following changes in impacts would result from the Elevated Structure Alternative.
Elevated Structure Alternative. The effects of the Elevated Structure Alternative would be more similar to the impacts discussed in Chapter 6 of the 2004 Draft EIS Appendix H for the Rebuild Alternative, rather than the Aerial Alternative, because the latter included construction of temporary aerial structures that would have added shadow and noise impacts to park and public access facilities along the waterfront. The current estimated construction period for the Elevated Structure Alternative is 10 years as compared with the Draft EIS estimate of 9 years (including preliminary utility relocation). The same pattern of construction impacts on waterfront uses and on Seattle Center described for the Tunnel Alternative is likely from the Elevated Structure Alternative. Olympic Sculpture Park: Under the Elevated Structure Alternative, the Olympic Sculpture Park would experience proximity impacts from increased traffic on the Broad Street Detour along the southerly boundary of the park. The elevated roadway between Xxxxxxx Avenue and the Alaskan Way surface street would add substantial visual intrusion, shadows, and noise to the southerly portion of the park. The 2004 Draft EIS Appendix H assessed impacts during the 8 years the detour was projected to be under construction or in use. Under the Elevated Structure Alternative, the Broad Street Detour would be in use for 4.25 years as compared with the estimated 8 years discussed in the Draft EIS.
Elevated Structure Alternative. The Elevated Structure Alternative would begin at the south with the same Whatcom Railyard options as described above for the Tunnel Alternative. In the central section, the existing aerial structure would be replaced with a rebuilt, double‐level aerial structure, which would be wider than the Rebuild Alternative evaluated in the Draft EIS, but not quite as wide as the Aerial Alternative. Ramps would be rebuilt at Columbia and Seneca Streets and Western and Xxxxxxx Avenues. There would be no lid structure to connect Xxxxxxxxxxx Park to the waterfront. The Battery Street Tunnel improvements and Partially Lowered Aurora would be the same as described for the Tunnel Alternative.
Elevated Structure Alternative. The Elevated Structure Alternative has only one option. In the south section, it would cross the railyard area by either reconfiguration or relocation of the Whatcom Railyard. In the central section, the viaduct would be replaced with a double‐level aerial structure with reconstructed ramps to Columbia and Seneca Streets and Western and Xxxxxxx Avenues. Unlike the Draft EIS Rebuild Alternative, the Elevated Structure Alternative would be approximately 20 feet wider than the existing viaduct in the central waterfront area to improve safety. There is no option for the north section—it is the same as described for the Tunnel Alternative with the Partially Lowered Aurora improvements.
Elevated Structure Alternative. The Rebuild Alternative evaluated in the Draft EIS did not include any improvements to the Battery Street Tunnel or Aurora Avenue N. The Elevated Structure Alternative includes such improvements. As such, the construction impacts to social resources now extend through the Belltown neighborhood and along Aurora Avenue N. The construction of the Elevated Structure Alternative, including the option to relocate the Whatcom Railyard, is proposed using the longer plan. This is the same construction plan evaluated in the Draft EIS. The Elevated Structure Alternative also incorporates the Broad Street Detour, which would increase traffic congestion and noise along the Broad Street corridor.
