  This article is motivated by the lack of empirical data on the performance of
commercially available Society of Automotive Engineers level one automated
driving systems. To address this, a set of car following experiments are
conducted to collect data from a 2015 luxury electric vehicle equipped with a
commercial adaptive cruise control (ACC) system. Velocity, relative velocity,
and spacing data collected during the experiments are used to calibrate an
optimal velocity relative velocity car following model for both the minimum and
maximum following settings. The string stability of both calibrated models is
assessed, and it is determined that the best-fit models are string unstable,
indicating they are not able to prevent all traffic disturbances from
amplifying into phantom jams. Based on the calibrated models, we identify the
consequences of the string unstable ACC system on synthetic and empirical lead
vehicle disturbances, highlighting that some disturbances can be dampened even
with string unstable commercial ACC platoons of moderate size.
