In honor of Bike To Work Day, here’s a pop quiz for Seattle readers.

Q. Which infrastructure project is too costly to fund?

a.) The $2.4 billion deep-bore tunnel*

b.) The $240 million Bicycle Master Plan

bmp cost

If you guessed “A”, nope! Easy mistake. The answer is “B.”

Here’s a bonus question.

Q. State law says that Seattle taxpayers are on the hook for cost overruns for which project?

a.) The deep-bore tunnel, a state highway

b.) The Bicycle Master Plan, a city project

Surely, nobody in Seattle would miss the answer to that one. (Folks who live elsewhere may be surprised to learn that the answer is “A.”)

Come to think of it, perhaps the best way to pay for the Bicycle Master Plan would be to build it on the sly, and book it as a “cost overrun” of the tunnel project. The additional funding we need for the bike plan would only add something like a 6% cost overrun, which would practically be a rounding error, if the history of these projects is any guide. Sure, us Seattle taxpayers would pick up the tab, but that’s okay: at least we’d be building something the voting public in town actually supports.

Speaking as a bike commuter, I’m delighted, just delighted, that a decade from now—about the time my son starts cycling — my city will boast the world’s largest bored tunnel, dedicated exclusively to driving at high speeds beneath downtown. What my city won’t have, of course, is enough decent bicycling infrastructure to make it safe for kids to travel on two wheels.

Take another look at the chart above. The green bar would pay for 450 miles of bicycling infrastructure that would touch every neighborhood in the city. Too bad there’s scant money to pay for it. The orange bar will pay for a few miles of new highway parallel to a 10-lane freeway just a mile away. And of course that’s the one officials are determined to build, no matter how much uncertainty there is about costs and funding.

So what do you think? Do we have a sustainability problem?

* Strictly speaking, the deep bore tunnel itself is “only” $1.96 billion. But add in the south end viaduct replacement, which is a necessary add-on to the tunnel, and you end up with a little more than $2.4 billion.