WHEN people here speak of the Oregon Trail, the name of the
route that brought thousands of settlers to the West nearly 150
years ago, chances are they are not nostalgically evoking
history but advocating a vision of the future. In Oregon, as in
dozens of other states, Americans are clamoring for places where
they can go from place to place without the aid of anything
motorized. A convergence of two fitness crazes - walking and
biking - with the filling up of open spaces has brought about
the emergence of the urban trail movement. Committed pedestrians
are building walkways in old railroad beds and constructing
paths from downtown areas to distant farmlands. It is not just
recreation or souls in need of a solitary walk that are behind
this burst of city trail-blazing; supporters of the movement say
many of the transportation problems of big cities could be
solved by bicycle commuters moving to work along the new trails.
In Seattle, thousands of bike commuters use the Burke-Gilman
Trail, a paved-over rail line