WSDOT has (basically) responded to McGinn’s report concerning the feasibility of light rail across the new bridge 520. McGinn’s report showed that unless the current design is modified, light rail will probably never be feasible across the bridge, but WSDOT says that light rail is possible across the span:
Will the new SR 520 floating bridge be able to accommodate light rail?
Yes. WSDOT engineers have designed the new SR 520 floating bridge so that additional supplemental pontoons could be added in the future to support the weight of light rail.
That response really seems, well, not true. The opening “yes” has little to do with the rest of the statement, because even without changes to the pontoons, the current design will effectively preclude light rail. (That’s the difference between “physically being able to carry trains” and “accommodating light rail.”) Additional pontoons are just one issue that McGinn’s report called out; it also spoke to two other concerns that would be significantly harder to accomplish with a retrofit. As we wrote earlier this week:
- The west approach (meaning through the arboretum) would have to be at least 10 feet wider than the current A+ alternative to accommodate light rail without having to significantly modify the structure later.
- Through the arboretum, the bridge must be wider (or have a gap) to allow light rail to enter and exit the center HOV lanes and diverge from the freeway.
While these changes would be difficult to add during a retrofit, we have no clue how much they would cost to accomplish if we do things “right” from the beginning. The difference is important: if voters choose to put light rail across 520 and the only marginal cost is adding more pontoons and installing rail infrastructure, we could be save hundreds of millions of dollars compared to retrofitting more difficult design changes. The cost and disruption would be so great that a retrofit of these changes is practically infeasible, meaning that light rail would never cross 520 even if all of the transportation experts said it should. (Which is a big assumption, since right now no single 520 alignment looks very useful.)
More after the jump…
If one thinks we should allow for the possibility of rail on the new 520 bridge, one should focus on the two design changes above and ignore McGinn’s pontoons recommendation which allow WSDOT to drive up the cost of estimates. For example, WSDOT writes:
First there is the cost of time. The state Attorney General’s office and the Federal Highway Administration estimate that an additional two years of time would be necessary to conduct the required environmental analysis. This would be essential since the current analysis assumes the four general-purpose and two transit/HOV lane configuration and does not address light rail.
Secondly, it would cost between $150 million and $200 million to construct the 30 additional pontoons and to install them on the floating bridge, along with the 77 pontoons required for the six-lane alternative. There would be other costs associated with the bridge deck expansion and other infrastructure, including rail lines.
While WSDOT argues about the cost of pontoons, it doesn’t mention any costs associated with the two design changes listed above. Since few are arguing for light rail across the bridge now, the first argument makes little sense. However, according to City Council analysis released yesterday, there may need to be an additional environmental review would need to be conducted if pontoons are built. Publicola reports:
Finally, the analysis found that although the state wouldn’t have to do additional environmental studies to widen the gap between eastbound and westbound 520 lanes over Foster Island to accommodate rail, adding pontoons would require a new environmental impact statement, and cost the state between $150 and $200 million.
WSDOT’s cost estimates and the impact of delay leads us to a conclusion: it doesn’t makes sense to build pontoons for light rail right now when adding them later is feasible.
But WSDOT is majorly wrong in its other statements. It’s misleading to say that light rail is feasible without McGinn’s other recommendations or some other design changes; WSDOT should not mislead the public. The region has to make a choice: allow for the possibility of light rail on 520 by changing the design slightly, or keep current design choices that will prevent light rail from ever crossing the bridge. WSDOT does not present these alternatives accurately.
Some transit supporters, like Ben, think that any light rail across 520 will be an ineffective waste of money; others, like Martin, think that allowing for the possibility of light rail makes sense if the cost is right. WSDOT has a duty to Seattle to present estimates for McGinn’s design recommendations, because if the marginal cost of construction is below the subjective marginal benefit of the possibility of rail then we should know. Just like rail advocates shouldn’t push for tracks that will go unused for decades, they should back off of the pontoons.
520 rail supporters — McGinn included — would be smart to admit that building extra pontoons before light rail is being put across the bridge might not make sense. That admission will allow advocates to point out the holes in WSDOT’s claims and could focus efforts on the two design changes above, as well as political arguments such as how to price the HOV lanes if they’re ever given to Sound Transit.
By keeping the pontoons in play, McGinn is allowing WSDOT to point out that just one of his recommendations would cost hundreds of millions of dollars and delay the project by years, without even studying his other, potentially reasonable recommendations.