I was working out the math in some upcoming posts about transportation, in which I intend to tackle the Columbia River Crossing, the expansion of light rail, the gas tax, and ODOT, and struggling with how to compare costs and make the comparisons meaningful and easy to follow. After a few hours of going through budgets, projections, and revenue statements, the eyes glaze over and "billions" begins to sound not much more expensive than "millions."
It occurred to me that we need a new unit of measurement, sized to the task at hand. Just as the millimeter is too small a unit to use to measure our height, the dollar is too small a unit to use to measure our spending on transportation.
We need a more convenient unit to measure transportation spending. I am inventing the "Sellwood," a unit of money that equals the cost to replace the Sellwood Bridge. I'm arbitrarily setting that at $200 million, which is where I think the cost of the bridge, not including the west side interchange, will end up, if we actually get around to building the thing in the next two or three years.
Here's the Sellwood in service: it will cost 1 Sellwood to replace the Sellwood Bridge. The Columbia River Crossing is estimated to cost about 15 Sellwoods, including 1 Sellwood already spent on planning and engineering. ODOT collects about 7 Sellwoods a biennium (3.5 per year) from the gas tax and the truck weight-mile tax. ODOT borrows 4.5 Sellwoods a biennium to finance road improvements, and pays 1 Sellwood a biennium (increasing rapidly) in debt service. ODOT's 2009-2011 budget (2 years) is 20 Sellwoods, of which 5 Sellwoods will come from running up debt. The proposed light rail line to Milwaukie will cost us 7 Sellwoods.
The Sellwood is the right size for the job; more importantly, it will remind us that when we spend money on one project, we take away money from another. Here's to the Sellwood!