Argument: Seattle has good experience with deep-bore tunnels
- Debate: Seattle deep-bore tunnel - pro argument.
Glenn Pascall. "Is deep-bore tunnel best hope to replace viaduct?" Puget Sound Business Journal. December 30th, 2007: "Seattle's tunneling history is more extensive than many residents realize. Red Robinson, lead geo-technician for locally-based engineers Shannon & Wilson, described several of the more than 100 tunnels in Seattle that total over 65 miles in length. The 64-foot wide Mount Baker Tunnel on I-90 is the world's largest soil ridge tunnel. Seattle City Council transportation committee chair Jan Drago added that in recent years, 'We've been building deep bore tunnels in Seattle -- Third Avenue, Beacon Hill, Brightwater.' In opening remarks, Drago noted that 'tunnel technology has changed significantly if not dramatically since we started searching for solutions to the viaduct.'"