  Characterizing the dependence of the orbital architectures and formation
environments on the eccentricity distribution of planets is vital for
understanding planet formation. In this work, we perform statistical
eccentricity studies of transiting exoplanets using transit durations measured
via Kepler combined with precise and accurate stellar radii from the
California-Kepler Survey and Gaia. Compared to previous works that
characterized the eccentricity distribution from transit durations, our
analysis benefits from both high precision stellar radii ($\sim$3%) and a large
sample of $\sim$1000 planets. We observe that that systems with only a single
observed transiting planet have a higher mean eccentricity ($\bar{e} \sim
0.21$) than systems with multiple transiting planets ($\bar{e} \sim 0.05$), in
agreement with previous studies. We confirm the preference for high and low
eccentricity subpopulations among the singly transiting systems. Finally, we
show suggestive new evidence that high $e$ planets in the Kepler sample are
preferentially found around high metallicity ([Fe/H] $>0$) stars. We conclude
by discussing the implications on planetary formation theories.
