  Whereas a very large number of sensors are available in the automotive field,
currently just a few of them, mostly proprioceptive ones, are used in
telematics, automotive insurance, and mobility safety research. In this paper,
we show that exteroceptive sensors, like microphones or cameras, could replace
proprioceptive ones in many fields. Our main motivation is to provide the
reader with alternative ideas for the development of telematics applications
when proprioceptive sensors are unusable for technological issues, privacy
concerns, or lack of availability in commercial devices. We first introduce a
taxonomy of sensors in telematics. Then, we review in detail all exteroceptive
sensors of some interest for vehicle telematics, highlighting advantages,
drawbacks, and availability in off-the-shelf devices. Successively, we present
a list of notable telematics services and applications in research and industry
like driving profiling or vehicular safety. For each of them, we report the
most recent and important works relying on exteroceptive sensors, as long as
the available datasets. We conclude showing open challenges using exteroceptive
sensors both for industry and research.
