My apologies in advance: this post will probably only interest readers who live in Cascadia’s most populous county; or who are fascinated by the details of transportation funding.

The Nov. 2 ballot in King County, Washington, where I live, includes a rather peculiar item that many people have asked me about: an advisory measure on transportation. It’s advisory because it’s just a poll. It doesn’t change any laws, appropriate any money, or put anyone in office.

Here’s the Voter Pamphlet description:

This advisory measure asks which tax source the voters in King County would prefer be used to support a transportation plan designed to relieve traffic congestion and increase safety through a mix of road and transit projects in King County. This plan would require voter approval at a future date. Which one of the following tax sources would you prefer be included in a plan to locally fund road and transit projects in King County?


  • a general sales tax
  • an excise tax on the value of motor vehicles
  • a flat tax on motor vehicles
  • an increase in the local gas tax
  • a tax on total annual vehicle miles traveled

I recommend pulling for the tax on the total annual vehicle miles traveled (VMT). It’s currently impractical to implement this tax, but this is a poll of preferences, not policy. And a VMT tax may be feasible within a few years. A VMT does the best job of getting prices to tell the truth: all driving, even in fuel-efficient vehicles, creates costs for nondrivers and society, such as road wear, noise, a nuisance to pedestrians and communities, and the risk of accident. A vehicle mile tax is the closest thing to a straight user fee for driving. (The idea is similar to pay-as-you-drive car insurance.)

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  • Gas taxes are my second choice—a close second—because they also vary with the amount of driving you do. Gas taxes also modestly encourage the use of more efficient vehicles. But they tend to reinforce the notion that gasoline consumption is the only problem created by cars. That’s why I mildly prefer the VMT option.

    Vehicle taxes—whether excise or flat—have virtually no effect on people’s transportation choices, but an excise tax on the value of motor vehicles is better than a flat one. For one thing, it’s more fair in terms of ability to pay. For another, more-valuable vehicles are usually driven more miles than less valuable ones.

    A general sales tax is my least favorite option. It’s viciously regressive in a state that already has a very regressive tax code. And, besides, transportation should pay for itself. Unlike education or defense or imunizing children or basic research, transportation is not a public good that deserves public subsidy.