The gist: Make the price of driving tell the truth through fuel taxes that fund alternative transportation.

The details: Drivers need roads, bridges, parking spaces, police, ambulances, and other services, but they pay only part of the associated costs through fuel taxes, vehicle registration and license fees, or parking charges.

Taxpayers--regardless of how much they drive--pick up the rest of the tab. Most Northwest jurisdictions enshrine in law the principle that all revenue from fuel and other vehicle taxes be spent on roadwork, but road spending often exceeds the revenue from these taxes.

A powerful reform would put in place the parallel principle--that only fuel and vehicle taxes go to the automotive infrastructure.

For example, the Northwest states spend a great deal of money on roads--almost $1 billion in a year in a recent year--from sources unrelated to driving, including property, sales, and income taxes.

This figure excludes what the region's cities and counties spend each year on services for motor vehicles, such as traffic policing, car fire protection, and traffic planning.

The revenue code also plays favorites toward cars. In British Columbia and Washington, buyers can subtract the value of trade-ins from the price of a new car before sales tax is calculated. And these jurisdictions and Idaho exempt motor fuels from retail sales taxes.

Northwesterners can curb the overuse of motor vehicles not by standing against them--they are, after all, incredibly useful machines--but through a countermove that rests on the user-pays principle.

Requiring that motor vehicles pay for all roadwork, coupled with even-handed tax treatment of cars and fuel, would push driving rates down and give other modes of travel a fair chance.