Every few seconds your
cellphone checks in with either a relay tower or a GPS system, which is how it's able to
perform the wonders of geolocation
on Google Maps or Yelp or whatever apps you use to tell you where you are and what's available around you.
When a person is texting or
performing other actions
on a
cellphone, that driver's eyes aren't
on the road and aren't searching for danger or potential problems.