Are you ready to pay for light rail to Fife?

The junk mail from "Roads & Transit," the marketing name for the proposed 9.5 percent sales tax, arrived at my house the other day. It says, on one side, "Turns out, it really is ALL ABOUT YOU." A little arrow points to the photo of a car stuck in traffic.

That's you.

Turn the card over and on one half is the 520 bridge. It says: Roads & Transit is all about you. On the other half it says ... and everyone else, too — and shows a light-rail car.

There is the message: You drive, they take the train.

It doesn't ask you to recall the last five times you used your car, and imagine doing the same tasks on their light-rail line. It doesn't ask you to think of what light rail will do for you — that is, to buy a train for yourself.

Why not?

Maybe it would be selfish to think of yourself. Maybe you are more interested in the grand vision, which is to get people out of their cars. All right; let us imagine a scenario. Suppose that because of global warming or peak oil or some other imperative, we have to cut car trips by 75 percent. How would we do it?

Limit the question to King County. It has more than a million destinations: homes, schools, businesses. Most are spread out, built by people with cars. Every destination is reachable by car. Most are also reachable by bus, given a little walking and waiting, and maybe a transfer. King County Metro has 244 bus routes that serve 9,141 bus stops.

At the cost of billions, Sound Transit is building one light-rail line. It will have 12 stops.

Back to our hypothetical. Suppose we want to cut car use 75 percent countywide and not leave people stranded. To do that, would we add to the system with 12 stops, in which another stop costs hundreds of millions of dollars? Or the system that has 9,141 stops, and in which stops can be added at a tiny fraction of that cost?

The question answers itself. We would buy buses and vans, because they could be put to use immediately and could go everywhere. They might run on hydrogen or biodiesel, but they would have rubber tires and run on the road. Perhaps they would have dedicated lanes.

We would also encourage carpooling, jitneys (collective taxis), motorbikes and bicycles, and maybe even build some bikeways. We would not build light rail because we would run out of money before we had enough of it.

The cut-75-percent scenario is one future, and maybe an unlikely one. The official future assumes that fuel remains affordable and that hundreds of thousands more people want to go places in King County. Call it the congestion scenario.

It's different in some ways. The light rail is not as obviously bad, particularly in the areas of densest population. But still there is the choice between extending a bus system with 9,141 stops and a light-rail system with 12 stops. Still, the costs of adding one station to light rail are hundreds of millions of dollars, while adding a bus and a driver (who can serve more than one stop) are in the hundreds of thousands; and still, if you try to serve even 5 percent of the population with light rail, you will run out of money first.

Seattle is a low-density city. It is not New York, and further, it does not want to become New York. And in Proposition 1, we are not talking about Seattle only, but building light rail to lower-density places like Shoreline and Lynnwood, Bellevue and Overlake, Federal Way and Fife.

Light rail to Fife. Imagine that. Imagine what it will cost, and how many people who now stream by Fife's car dealerships will get out of their cars, buy a ticket and wait for the train that stops at South Federal Way, Federal Way, Redondo, Des Moines, South 200th Street, Sea-Tac Airport, Highway 518, and on up the Rainier Valley into downtown Seattle.

Imagine doing it yourself.

You will pay for it. Do you want it — for yourself?

Bruce Ramsey's column appears regularly on editorial pages of The Times. His e-mail address is bramsey@seattletimes.com for a podcast Q&A with the author, go to Opinion at seattletimes.com