Simulations of the Alaskan Way Replacement Options

Cascadia Center for Regional Development has long supported a deep-bored tunnel option to replace the aging Alaskan Way Viaduct. The approach will open up the waterfront, improve views, and provide new public parks and open spaces, all while maintaining the necessary capacity for through-traffic and freight. The Washington State Department of Transportation has recently produced two simulations to demonstrate the impact the project could have thousands of people who live and work downtown or travel through the corridor.

The following excerpt is drawn from the WSDOT web site and the videos are available below.

“Trying to convey the changes that will result from a large transportation project is a challenge. For smaller projects – repaving a road, adding a roundabout – it’s easy for people to picture what the end result will be. For a project like the SR 99 bored tunnel that will replace the Alaskan Way Viaduct, it’s a little more complicated.

Not only does the proposed replacement include an almost two-mile-long bored tunnel beneath downtown, we also plan to rebuild the surface street along the waterfront. People ask – What will the tunnel look like? How will I be able to access it? How will the new waterfront street be different than what exists today? Well, we now have some new tools to help provide answers.”

You can visit the Alaskan Way Viaduct program Web site at to learn more about these and other improvements that are part of the viaduct’s replacement.