Meaningless Driving Statistics

This MSN article reports the results of a focus group composed of 30 bad drivers (people with a large number of accidents or traffic violations in the three years). The article contains a plethora of totally meaningless statistics, including:

• 77% of bad drivers say they frequently or occasionally talk on cell phones while driving.
• 60% of bad drivers say they frequently or occasionally eat while driving.
• 60% of bad drivers say they get frustrated when SUVs or other large vehicles obstruct their vision.
• Nearly all bad drivers say they change their driving behavior when they know police are nearby.
• 93% of bad drivers say they listen to the radio while driving.

“If your answers agree with the answers from the focus group,” says the article, “it's likely you tend to be a more aggressive driver than average.” But the figures given show nothing of the sort, because they provide no point of comparison. The article provides no comparable figures for a control group of typical drivers, and therefore we have no idea whether the bad drivers’ percentages are relatively large or not. I wouldn’t be surprised, for instance, to find out that 93% of all drivers listen to the radio, or that 60% of all drivers occasionally eat while driving. And just about everyone I know drives extra carefully when police are around.

The point is not, of course, that none of these behaviors are dangerous. The point is that we need more information in order to distinguish the truly dangerous activities from the innocuous ones.