8/7/2007Delaware Report Uses Bad Math to Support Red Light Cameras
Delaware Department of Transportation fudges numbers to make red light cameras look better in a report to the state legislature.
The Delaware Department of Transportation (DelDOT) released an audit report at the end of February arguing that its red light camera initiative "has largely been successful" since it began in 2004. Armed with these findings, DelDOT urged the legislature to remove any legal restrictions on the number of cameras that the agency could install in the state because, in just two years, photo ticketing has had a significant impact.
"The downward trend of violations provides an indication that traffic's attention is more appropriately devoted to traffic signals," the study concluded. "The downward trend in all four categories of crashes is the outcome of this effect and this desired outcome has begun to unfold at a relatively early time in the program's history. While the program's successes have not been entirely across the board at all intersections, the scientific approach utilized for intersection selection and program management remains untainted by non-scientific influences."
But at least one observer is saying: not so fast.
This independent researcher discovered that DelDOT's data reflected basic mathematical errors. A table containing the number of "red light crashes" on a before and after basis simply did not add the numbers properly. This error was compounded by the fact that DelDOT did not provide raw data for number of rear end collisions or the total number of accidents, rendering the remaining data elements questionable. View excerpt of the errors on page 36. Our comparison of the "red light running" crash charts with its corresponding data table showed that the charts did not correctly report the data, even when added properly.
Even though the report compared three years of "before" crash data to just one or two years of after data, the report intentionally threw out three months of "after data" from the final results.
"The first three months of this period were not included in the 'after' analyses to allow drivers to be acclimated to the presence of red light enforcement equipment," the report admitted. (Page 9)
Including these figures may have diminished the positive result that DelDOT intended to provide regarding the profitable program. From 2004 to 2006, red light cameras billed motorists $9,353,722.23 with Nestor Inc. pocketing $4,659,713.78 of this amount in exchange for operating them. Nestor keeps a flat $4390 monthly fee for each intersection approach with a camera (currently there are 31 approaches in five localities) plus a $13.50 bounty for every citation it is able to issue. Out-of-state motorists -- primarily from Pennsylvania, Maryland and New Jersey -- ignored 18,510 tickets worth $458,000.
According to the audit, cities used the red light camera revenue to fund police department spending. Although the cities with red light camera programs were required by law to provide an accounting of how program money was spent, many did not comply. One city even raised questions about the reliability of the cameras, but the report did not investigate.
"An enforcement official from the City of Dover remarked that the reliability of technology needed improvement," the report stated. "Clarification and additional information further to this comment was not yet secured as of the time of submission of this report." (page 44)
Several long-term, independent studies of red light cameras conducted over the past decade have found that the devices lead to an overall increase in the number of accidents and injuries. The full DelDOT report is available in a 2.3mb PDF file at the source link below.