A brown-bag discussion of traffic diversion from the deep-bore tunnel this afternoon raised more questions than it answered, and highlighted the uncertainties around the state and city’s preferred option for replacing the Alaskan Way Viaduct.
Tunnel supporters and the council’s lone tunnel opponent, Mike O’Brien, fired dueling loaded questions at Nelson/Nygaard consultant Tim Payne, who did his best to lay out the advantages and disadvantages of building a tunnel and tolling it at the maximum possible level (which happens to be the level required to raise the $400 million the state hopes to get from tolling). Some highlights:
• The state really has no idea how traffic will respond to tunnel construction. Because the model the state used in coming up with its traffic-diversion figures assumes “that one day we have no tunnel and the next day we have a tunnel with tolls,” it could be over- or underestimating the number of cars that will divert onto surface streets downtown, Payne said.
• The state’s analysis didn’t take into account the fact that traffic volumes in Seattle are actually declining—in fact, it assumes a growth in “trips” to and from downtown of nearly a third by 2015—it also fails to consider that Metro and other transit agencies that serve downtown Seattle are facing massive potential cuts to service, undermining efforts to increase transit use. There could be “a pretty wide swing in either direction”—toward more single-occupant vehicles or toward more transit use—depending on whether Metro gets more funding, Payne said.
• Metro hasn’t done a good job of coordinating with the city and state on getting transit through downtown during and after tunnel construction, Payne said. “There’s no specific plans for getting transit around additional congestion. That is an issue we should pay some attention to, because transit is going to be very important as one of the tools,” Payne said. “If I could be king for a day or czar of transit … the first thing I would have done is laid down where I wanted the transit lines to be” before planning the tunnel itself, he added.
• Alarmingly (at least for those who think the city and state should be working to reduce vehicle miles traveled and greenhouse gas emissions), the state has apparently put little thought into how the tunnel could help advance that goal. Instead, Payne said the tunnel will create a “significant amount of congestion at many downtown intersections,” making VMT and greenhouse-gas emissions worse, not better.
He compared the situation to a family that heads for Disneyland, but ends up driving to Everett instead. “We’re going to get to Disneyland, but we’re going to have to find a place to turn around first.”
• Finally, O’Brien and Payne bickered a little over whether the state had really studied the surface/transit option for replacing the viaduct. Payne said he had “just picked one” of three potential surface/transit options studied by the state; O’Brien responded that the options the state studied did not include improvements to I-5.
