Bayes Law and Traffic Problems

http://sciencemode.com/2009/03/30/statistical-road-safety/

The article above discusses how some civil engineers in Connecticut used Bayes Theorem to predict the expected crash rates at specific locations around the city instead of using traffic calming devices in order to reduce traffic incidents. According to the article, using this method allowed them to "predict the expected crash rate at specific sites around the city assuming that no safety and traffic-calming measures had been put in place. Study site crash rates with and without treatment for the same time period were compared. They then also compared this with a conventional analysis to weed out any analytical biases." In the end, they found that sites that had fewer accidents before, had fewer accidents later.