One of the stronger objections to my quasi-support for a rebuilt viaduct is that the City of Seattle would not realize the $700m in savings between that project and the Deep-Bore Tunnel.
In principle, I suppose WSDOT could demolish the current structure and walk away, leaving Seattle to clear the rubble and do something with the space. Although that’s essentially surface-lite, I don’t think it’s a reasonable possibility. The State has consistently committed to funding the main roadway, and has demonstrated deep interest in preserving the flow of cars and freight through downtown.
Under the DBT plan, the roadway and construction mitigation amounts to $3.1 billion dollars. This is funded out of $1.8 billion in gas taxes, $600m in other state and federal funds, $300m from the Port of Seattle, and $400m from tolls.
The final iteration of the rebuild allocates $2.9 billion to similar projects, plus $103m for I-5 improvements. It would be absolutely unprecedented for WSDOT to not fund the state or interstate highway. Interestingly, the seawall is viewed as so integral to the viaduct that it’s included in the same line item in the report. But let’s assume that the State leaves that with Seattle to the tune of $244m*. Whether the $100-300m in savings is captured by the Port, toll payers, the highway fund, or even Seattle would of course be a matter of negotiation. In no case, though, would I presume that a dime of the State’s money would go to transit aside from the customary construction mitigation.
Seattle could be tasked with funding $234m in street improvements under the rebuild plan. The DBT price tag for the City is $811m*, leaving a savings of $333-577m seawall-depending. Now it’s certainly not the case that that money is automatically programmed into transit. However, transit advocates have a much better shot with the Seattle City Council than the Washington Legislature. We certainly have a strong claim on the $267m required to make the transit part of the viaduct plan work.
Then, of course, you have overruns and tunneling risk. But you’ve heard about those.
* Accounting for the flood district’s $30m contribution to the seawall.