  Solomon and Elkin constructed a shortcutting scheme for weighted trees which
results in a 1-spanner for the tree metric induced by the input tree. The
spanner has logarithmic lightness, logarithmic diameter, a linear number of
edges and bounded degree (provided the input tree has bounded degree). This
spanner has been applied in a series of papers devoted to designing bounded
degree, low-diameter, low-weight $(1+\epsilon)$-spanners in Euclidean and
doubling metrics. In this paper, we present a simple local routing algorithm
for this tree metric spanner. The algorithm has a routing ratio of 1, is
guaranteed to terminate after $O(\log n)$ hops and requires $O(\Delta \log n)$
bits of storage per vertex where $\Delta$ is the maximum degree of the tree on
which the spanner is constructed. This local routing algorithm can be adapted
to a local routing algorithm for a doubling metric spanner which makes use of
the shortcutting scheme.
