SEATTLE — Tolling on the new State Route 99 tunnel has been delayed until at least fall.

The delay hinges on the Washington State Department of Transportation’s transition to a new back office system, which includes functions like customer service, operations, and account management.

“It all centers around making sure this new system is ready to go,” said Reema Griffith, executive director of the Washington State Transportation Commission.

Griffith said Wednesday there will have to be a full system test in the SR 99 tunnel before it goes live and tolling systems around the state can transition to it.

Previously transportation officials had said tolling could go live by early summer.

The new back office system is just one factor impacting the tolling timeline. WSDOT said back in February that it wanted to wait until demolition of the main waterfront portion of the Alaskan Way Viaduct was complete. Crews are now about halfway done demolishing the entire viaduct, and nearly finished with the waterfront section.

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The transportation commission has already set tolling rates, but if the tolling start date gets pushed back beyond fall, Griffith said the commission may need to re-evaluate if collections will still cover expenses. If not, it could re-assess tolling rates.

“Right now we’re confident that we’re still in the window where they’re accurate and sustainable for what we assumed,” Griffith said.