The giant drill digging the new Highway 99 tunnel under downtown Seattle has almost completed its mission. But, it's been a bumpy road for the drill known as Bertha over the past four years. Seattle Times Traffic Lab reporter Jessica Lee breaks down this massive project.
Bertha finally nears the finish line
The giant drill digging the new Highway 99 tunnel under downtown Seattle has almost completed its mission. But, it's been a bumpy road for the drill known as Bertha over the past four years.
