  Most of our knowledge of the radio morphology and kinematics of X-ray binary
partially synchrotron self-absorbed compact jets (hereafter compact jets) is
based on the observations of GRS~1915+105 which has the most prominent compact
jet. Yet, the compact jet bulk velocity, $v$, is poorly constrained in the
literature, $0.07 < v/c < 0.98$. In spite of this uncertainty, compact jets are
often unified with relativistic jets in active galactic nuclei. We have
estimated $v$ as part of a temporal analysis of GRS~1915+105 jets in "high
plateau states" (HPS). We define the HPS as a state showing a hard X-ray
spectrum and low level of long-term ($>10$s) X-ray activity associated with 15
GHz flux density $>70$ mJy for $>7$ consecutive days. The radio emission is
associated with compact jet emission. Two HPS were monitored at 15 GHz during
their termination with e-folding times of 3.8 hrs and 8.6 hrs. We combine this
time scale with the scale of spatial variation of the linear source of a VLBA
image preceding the fade of one of these HPS in order to estimate the jet
speed. Our assumption that the reduction in radio emissivity propagates as an
approximate discontinuity down the HPS jet (leaving a weak jet in its wake)
indicates $0.17 <v/c< 0.43$. This agrees closely with the only other existing
$v$ estimates that are derived directly from radio images, jet asymmetry
produced by Doppler enhancement.
