http://www.lcsun-news.com/las_cruces-opinion/ci_15096730

Clinton R. Lanier: The red-light cameras in review: How much success?By Clinton R. Lanier / For the Sun-News
Posted: 05/17/2010 01:00:00 AM MDT

Las Cruces— It seems I have a different definition of "success" than many on the City Council. What other reason can explain my continued doubt about the traffic enforcement cameras (i.e. red-light cameras) installed in four intersections throughout the city. Now I know that questioning the validity of these cameras (or the council's decisions) is not popular, but I seriously have to wonder how, with all of the controversy, questioning and division these light have caused, officials can look at the year-end data and say, "Wow, it worked!"

According to what was presented at the May 10 council work session, the total number of crashes at three intersections equipped with the cameras did not decrease, but actually increased from 53 to 60 during the single year they've been in operation. According to Dan Soriano, traffic engineering administrator for the city of Las Cruces, there has been a rash of rear-end collisions at each of the intersections, which would thereby explain the increase in collisions.

The increase in accidents was actually an increase in what's called "property damage only" (PDO) crashes (in other words, an increase in collisions that did not result in injuries). And there has been a decrease in accidents resulting in injury (by two), and one less fatality than the previous year.

But now this is where the explanation gets tricky. See, the Las Cruces traffic engineers assigned what they call a "severity index" to the data. They figure the severity

index (SI) by multiplying the number of injuries by five, adding that to the number of fatalities multiplied by 10, and then by finally adding that to the PDO. You've got to stay with me on this, because it's getting good.
At this point, the SI - the severity index by which they are proclaiming success-for 2008-2009 (the year prior to the installation of the red light cameras) is 142. Conversely, the SI for 2009-2010 (after the installation of the red light cameras) is 132.

Mr. Soriano, after pointing out this difference, told us that this is the measurement by which traffic engineers like himself deem success. One less fatality, two less injuries, and a severity index decrease by 10. So, it worked, right?

What he failed to mention - what nobody has pointed out - was that the single fatality used to increase the 2008-2009 severity index occurred in June of 2008 and was caused by two drunk drivers, one of which died.

Now, I don't know about you, but I seriously doubt that the red-light cameras would have made a smidgen of difference in the actions of the drivers involved in that accident. Already impaired by alcohol and dangerous behind the wheel, I simply can't see them stopping for fear of having their picture taken.

And without this data thrown conveniently into the equation, our severity index drops to 132, exactly where it was the year before they decided to install these things. Does it still sound like it worked?

And what about years prior to the 2008-2009 year used for comparison data? At these three intersections what were the injuries and fatalities in previous years? Shouldn't we be given more data than a 12-month's span with a single deviant statistic (in the form of a drunk driver who died)?

I'd like to point out that, as in the case of the rise in rear-end collisions the fact that there has been no marked decrease in accidents should come as no surprise. One of the most comprehensive studies conducted on the effects of red-light cameras found that total crashes at intersections with red-light cameras increased (you read that right, increased) by 40 percent (the study was conducted by the Urban Transit Institute and was at first rejected but has since been validated in two subsequent studies).

This was explained by an increase in "property damage only" crashes by 40-50 percent and a "statistically insignificant estimated effect on severe" accidents (in other words, little to no change in the type of crashes used to justify the red light cameras here). What makes this study different from much of the other research is the larger size of the pool studied, and the extended length of the data measured.

I know there are those who would choose not to believe the data and would rather believe that because they see people slowing down, and because they feel themselves slowing down, the red-light cameras must be working.

That's fine. But I still don't believe that gut instinct is the way to govern a city.

And in the end, the contract our city has signed with Redflex kind of makes the point moot anyway. We are locked into another four years of these cameras, because breaching the contract would be a costly path to travel. And after all, with all the money they make off us why would they let us out of it?

However, we do have the choice to not place any more of these things around our city. But from the conversation that occurred after the presentation, I don't think this is likely. Instead, councilors seemed happy to talk about where to put the next set of cameras (even though it was pointed out that, statistically, the remaining intersections to choose from suffered from even fewer collisions than those which already had the cameras). Further, our mayor also discussed putting mobile units up around town.

I'd like to ask the council to instead sit down and really look at the data produced over the last year. Look at the studies - the recent, unbiased studies-that comprehensively look at the results of red-light cameras in other communities. Look at those cities and municipalities that, after using the red-light cameras for years, have now decided to take them down. Yes, even look at our data un-skewed and unbiased (although I know it may seem unusually narrow-minded to do so). Look at all these things, and then ask if it's really been a success.

Clinton R. Lanier, PhD (Rhetoric and Professional Communication, NMSU) is a Las Cruces resident and assistant professor at the New Mexico Institute of Mining and Technology in Socorro.
 

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