DX Rider

I know it isn't exactly hard science, but the Discovery channel TV show 'Mythbusters' did an episode on driving hazards. They tested the participating cast members driving skills at the California Highway Patrols training course, which simulates various traffic conditions, hazards, and obstacles.

The first test was driving while sober and no cellphone. The second test was done when the participants were legally drunk, just over .08. The third test was done when the drivers were sober, but talking via a cellphone to another cast member who was not in the vehicle.

They tested 3-4 different people. In each case they could not find a discernable difference between the drivers perfomance while they were drunk and while they were talking on a cellphone, but in both cases there was a noticeable drop in each drivers performance when compared to how they peformed in the first or "control" test. In some cases the drivers performed worse while they were talking on a cellphone than while they were drunk.

Also, the course wasn't changed between tests. So the test subjects should have actually been better at anticipating the various parts of the course, which would have meant they peformed better after each repetititon. That was not the case.