Dracthen

The town of Drachten in the northern part of the Netherlands took its main traffic intersection and changed it drastically in 2003 -- all traffic signs and lights were removed! Below are pictures from before and after the rebuilding of the city square.




My favorite note from the summarizing report is that respondents think the traffic situation is less safe now (appendix 6c from the report), whereas the number of accidents has fallen to under 20% of previous levels. I think something called the Peltzman effect is behind the discrepancy between the increased safety but decreased view of safety. When human beings feel safe, they might engage in riskier behavior. By playing on the fears of people, the intersection has (so far) been much safer. I have previously blogged about this effect in a post on condoms.

Oddly enough, people ranked the "quality" of the re-designed space much better than before, even though they thought the re-design was less safe. In addition, the transit times across the intersection improved.

I think this effect has strong implications for how we can misunderstand our own rationality, and helps explain why it is important to study information objectively by examining accident rates and transit times, getting a full picture of how our emotions steer us in all situations.

Tip of the hat to reddit for still providing signal, even though most of your links are now noise.

Copyright note - the publication with these pictures didn't include explicit copyright information, but did contain a logo for a sponsoring institution, a Gemeente, meaning they should be in the public domain. If you are a random visitor with more information, please let me know if you are aware of the copyright situation of these photographs.

Blame Condoms or Human Nature?

Do condoms spread HIV? Some recent comments by the Pope are causing quite a stir. But the Pope might be right. At play is something called the Peltzmann effect or risk compensation. When humans feel safer, they sometimes engage in riskier behavior. With the "safety" of a condom, people almost certainly engage in sex they would not normally have. Too much safer sex can be more dangerous than a little risky sex. Safer sex still has risks.

I wish I had time to dig into this, but I'm hosed.

EDIT: The exact comments under question are that HIV/AIDS in Africa is:

a tragedy that cannot be overcome by money alone, that cannot be overcome through the distribution of condoms, which can even increase the problem

The part about condoms sounds reasonable to me. The part about money is pretty non-sensical. He asserts a bit of wackoness right after, when he claims:

the traditional teaching of the Church has proven to be the only failsafe way to prevent the spread of HIV/Aids

That is bull$#!+.