Basic logic problems: The roads are safer, but why?

There is nothing like traffic safety to bring out the best examples of logic problems in media stories. Recession Bright Spot: Less Highway Deaths at CBS News provides a good example.

First is the citation of economic recession as a cause of lower traffic fatalities. This is a classic correlation versus causation mixup. There is also a definition problem as it is not obvious whether it is the total fatalities or a rate of fatalities that stimulated the report. It turns out it was both

Preliminary figures released by the government Monday show that 37,313 people died in motor vehicle traffic crashes last year. That’s 9.1 percent lower than the year before, when 41,059 died, and the fewest since 1961, when there were 36,285 deaths.

A different measure, also offering good news, was the fatality rate, the number of deaths per 100 million vehicle miles traveled. It was 1.28 in 2008, the lowest on record. A year earlier it was 1.36.

That is followed by a reiteration of the report’s propaganda:

“The silver lining in a bad economy is that people drive less, and so the number of deaths go down,” said Adrian Lund, president of the Insurance Institute for Highway Safety

If the Insurance Institute can’t even figure out that a reduced rate is not the same as driving less it is no wonder the insurance industry is a mess. It would be reasonable to assume that more cars are on the road now than in 1961, the reference year in this report and that means that there must have been a significant drop in the rate in order for the total to be lower now than then. The record low rate only gets brief mention. It is key that the rate of fatalities has dropped over the years because that means fewer traffic fatalities even with more people on the road. Why is this so?

There are clues in the report.

In addition to fewer miles logged by drivers worried about expenses, experts also cited record-high seat-belt use, tighter enforcement of drunken driving laws and the work of advocacy groups that encourage safer driving habits. … Seat belt use in 2008 climbed to 83 percent, a record.

Why can’t the media help in understanding reality rather than promulgating propaganda?

There are several memes at play here. One is the voyeuristic obsession with the dead as also seen in the media hungering to portray military coffins. Another is economic misery whether it really exists or not. There is also the bias towards government saving you from those awful things (death and recession) as seen in the mention of seat belt laws and safety groups and states improving enforcement laws. That bias is away from such things as personal responsibility and technology improvements.

Like the mantra about speed limits, this sort of reporting carefully avoids the actual data that is collected about traffic crashes and fatalities and ignores the role of the driver. The advances in vehicle safety technology that are perhaps the most visible changes in both roads and vehicles gets very little notice. It really is amazing that such progress is made even with the propaganda headwind.

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