Tracking progress until the tunnel is ready for traffic

When Bertha finished digging on April 4, 2017, it marked the end of one critical element in the work of building the new SR 99 tunnel. It also marked the end of a straightforward, if simplified, way to track progress on building the tunnel (distance tunneled).

With Bertha’s disassembly nearly complete, we are shifting our focus to the other elements of work remaining before the tunnel is ready for traffic. This week we debut a new way to track this progress.

Screen shot from the new progress tracker

Our new Latest Construction Progress page contains a clickable map that tracks progress on three main elements remaining in tunnel work:

  • The interior structures of the tunnel
  • The electrical rooms
  • The mechanical, electrical and plumbing systems


The interior structures are the walls and decks that make up the highway within the tunnel. (Crews started on these elements long before Bertha finished tunneling.) The electrical rooms, spread throughout the tunnel, house and route the tunnel’s electrical systems. And the mechanical, electrical and plumbing systems will make the tunnel function properly; these systems include ventilation, fire suppression, and traffic cameras.

We’ve discussed these systems before, but this new tracker is a way to visualize their progress as crews build and install them in the tunnel (most elements being installed in a linear fashion from south to north). 

*Update Aug. 15* Close followers of the project have noticed that the distances from the weekly interior structures PDF report didn't match the distances in this new tracker. Today we updated the new progress tracker with those latest distances. The discrepancy is due to different reporting deadlines between the two reports. We will be discontinuing the PDF report in favor of this new web tracker, which provides a wider view of the progress crews are making. The new tracker will be updated monthly, with a lag between the work and the report. We will continue to share major progress milestones on our home page and via the program Twitter account.