The SA article mentions Houston, a notoriously horrible city to drive in (concentric freeway rings, I swear). It pulled data from Texas from before 2010, and I know at least some municipalities were shortening their yellows then to encourage short stopping. It also studies changes in behavior after the punishment tool has been removed, so the drivers are already operating with years of conditioning. They even referenced the study that showed that the number of people running red lights in Virginia dropped 67% after red light cameras were installed? I need to look a little bit closer at their statistical analysis to see what confidence threshold they were using to determine that the reduction in accidents that they did see was not statistically significant, but overall I’m not that impressed by one study from a borderline pop science magazine.
The SA article mentions Houston, a notoriously horrible city to drive in (concentric freeway rings, I swear). It pulled data from Texas from before 2010, and I know at least some municipalities were shortening their yellows then to encourage short stopping. It also studies changes in behavior after the punishment tool has been removed, so the drivers are already operating with years of conditioning. They even referenced the study that showed that the number of people running red lights in Virginia dropped 67% after red light cameras were installed? I need to look a little bit closer at their statistical analysis to see what confidence threshold they were using to determine that the reduction in accidents that they did see was not statistically significant, but overall I’m not that impressed by one study from a borderline pop science magazine.
Meta-analysis is the way to go.