  Advanced driver assistance systems (ADAS) are increasingly prevalent in the
vehicle fleet, significantly impacting safety and capacity. Transportation
agencies struggle to plan for these effects as ADAS availability is not tracked
in vehicle registration databases. This paper examines methods to leverage
existing public reports and databases to estimate the proportion of vehicles
equipped with or utilizing Levels 1 and 2 ADAS technologies in the United
States. Findings indicate that in 2022, between 8% and 25% of vehicles were
equipped with various ADAS features, though actual usage rates were lower due
to driver deactivation. The study proposes strategies to enhance estimates,
including analyzing crash data, expanding event data recorder capabilities,
conducting naturalistic driving studies, and collaborating with manufacturers
to determine installation rates.
