GB
Chief Eating Officer
I do not think that is much of a difference.I believe the difference between talking on the phone and talking to someone in the passenger seat is that the person in the passenger seat can see what is going on the road and knows when to shut up and let you concentrate. The person on the cell phone only sees what is going on in their own location.
For one thing, just because they can see what is going on in front of them does not mean they will be able to alert the driver with enough time for the driver to react. When accidents happen it is often because of split second decisions. Also very often, the person in the passengers seat is not even looking at the road. I know when my wife is a passenger and I am driving she is looking at me when talking to me or she might be looking at the kids behind us or reading a magazine or looking at the car next to us.