The Seattle area needs a variety of measures to fix its transportation woes (light rail, buses, streetcars, etc). Never mind that many people are waiting for a perfect, inexpensive, painless solution.
Instead, consider what works in Amsterdam:
Within the center of Amsterdam, trams are the kings of the roads; there are very few bus lines that travel strictly within the center, and parking is a hassle, discouraging driving. Taking the tram is easy because of the multitude of lines, speed, comfort, frequency, and affordable price.
Providing a practical alternative to driving alone (and lessening the incentives for driving) has led to increasing ridership, fewer accidents and -- get this -- a transit system that's even profitable. Of course, they had to start somewhere.