Your car, when you are driving in it, is a potentially deadly machine. With eyes on the road and no distractions, you can still hurt yourself or others without meaning to do so.
With your cellphone held up to your ear, you are an additional threat.
You forget to– or neglect to use your turn signal.
You are less likely to monitor your speed.
And you can barely look out for others. Your cellphone makes you a defenseless driver.
So, either get and use a bluetooth or speakerphone feature or hang up the phone! Some of us are making it our main mission to get somewhere safely.