  We have investigated a series of superconducting bridges based on homogeneous
amorphous WSi and MoSi films, with bridge widths w ranging from 2 um to 1000 um
and film thicknesses d ~ 4-6 nm and 100 nm. Upon decreasing the bridge widths
below the respective Pearl lengths, we observe in all cases distinct changes in
the characteristics of the resistive transitions to superconductivity. For each
of the films, the resistivity curves R(B,T) separate at a well-defined and
field-dependent temperature T*(B) with decreasing the temperature, resulting in
a dramatic suppression of the resistivity and a sharpening of the transitions
with decreasing bridge width w. The associated excess conductivity in all the
bridges scales as 1/w, which may suggest the presence of a highly conducting
region that is dominating the electric transport in narrow bridges. We argue
that this effect can only be observed in materials with sufficiently weak
vortex pinning.
