DelDot Produces Questionable Report in Favor of Their Own Red Light Cameras

July 29, 2007

A reporter from the Delaware News Journal contacted me a few days ago to ask my opinion about the new report issued by DelDot (Delaware Dept. of Transportation), Electronic Red Light Safety Program “after” Analyses Summary. According to the journalist, the report gave a glowing summary of Delaware’s Pilot program to equip the state with red light cameras which automatically ticket motorists. This came as a great shock to me since so many other states have had overwhelmingly negative results using similar systems, and I found it hard to believe that Delaware had achieved such dramatically different results.

For example, here are some findings from other states:

  • Maryland: 40% increase in rear end accidents immediately following installation of red light cameras, $2.85 million in revenue
  • Georgia: a 21% increase in accidents, ~ $1 million in revenue following red light camera installation
  • Virginia: The cameras are correlated with a 7-24% increase in total injury, as well as a 50-71% increase in rear-end
    crashes related to the presence of a red light.(Source
  • Ontario:
    “After evaluating the performance of red light cameras at 68 sites over two years, the report concluded that jurisdictions using photo enforcement experienced an overall increase in property damage accidents of 18.5 percent coupled with a 4.9 percent increase in fatal and injury rear-end collisions. Rear-end collisions involving property damage alone jumped 49.9 percent.” (Source:

The results seem to contradict the report issued by DelDot. However, I hadn’t read the report yet, so I asked if I could call the reporter back after I had some time to dig through it.

In the executive summary at the beginning, some rather impressive results are claimed:


After going through the report, I found several problems that DelDot overlooked:

  1. Basic mathematical errors (addition)
  2. No control group
  3. Throwing out important data

1. Basic Mathematical Errors (Addition)


(From page 36)

4 rows of data are just plain added incorrectly. 0 + 1 + 0 + 0 is not equal to 2. The fact that this didn’t happen once, but 4 times should call into question how thorough DelDot was with this entire report.

I spoke with Michael Svaby, DelDot’s Project Manager for the Red Light Camera program, who was kind enough answer my questions. He acknowledged inconsistencies in DelDot’s additions, but did not want to call them errors. He promised to get back to me with confirmed numbers.

2. No Control Group

There’s just no control group. One of the basic requirements for any scientific study is to use an unaltered control group to insure accurate data analysis.

Take this hypothetical example: if a study found that accidents had dropped 10% on I-95 in the state of Delaware, you might say that Delawarians are better drivers. But if accidents also dropped 10% in the Pennsylvania section of I-95, then our previous assumption about Delaware drivers suddenly doesn’t have as much weight to it. Furthermore, if the national accident average dropped by 25%, then perhaps we (Delawarians) might be doing something wrong.

Mr. Svaby informed me that in the 3 months DelDot was given to complete the report, they did not have enough time to use a control group. My response was that this was a vital step in any objective scientific research. This was acknowledged, but again, not enough time. So the DelDot report didn’t bother to use a control group, and therefore we have nothing to compare their results to, and its hard to put any weight behind their numbers.

3. Omitting Data that Goes Against Your Survey

Even red light camera proponents will occasionally admit that red light cameras will cause an increase in accidents, although they dismiss these accidents as being “slight and temporary”, meaning that they occur right after a red light camera installation. DelDot, in their report, intentionally removed the first 3 months of accident data after they installed each red light camera. According to Mr. Svaby, this was because of the “adjustment period” drivers experienced when going through the lights.

When asked about the data that was omitted, Mr. Svaby could not remember if there was a significant amount of crashes during that time, and generally could not recall any details about that information, but promised to provide it.

For example, on page 9:

After Crashes

So DelDot just didn’t include the first 3 months of crash data after the lights were installed. After looking at the previous errors data reporting, I really have to question this decision. Furthermore, their excuse about drivers needing to get “acclimated” to the equipment doesn’t hold much water, since so many other states (see 1st paragraph for links) have found that drivers never become acclimated to the equipment.

Does it get any worse? (Money)

Yes it does. One of the motivating factors for installing the lights was no doubt to also increase ticket revenue that the state could use for highway projects or related expenditures. Below the revenue/costs table for the red light camera system. revenue 2003-2005

Nestor, the company we have outsourced our red light law enforcement to has collected ~ $4.7 million in 3 years. That money we will never see again, and we just shipped it right out of Delaware’s economy and into a private firm. Previously, when you got a ticket, it at least went to the State. It could then be used for police salaries or highway repair. But not in this case.

Also, there aren’t any items related to administration. Who works with the vendor? What about the court costs? What about the people at DelDot preparing this report (It took 3 months, after all)? Sure these, and likely others I have missed, are costs that should be included.


I do not believe that legislatures ever meant for this to happen, and it is likely that they were handed some very questionable data and assured it was Gospel. On the surface, Red Light Cameras seem to be a win-win for the government in their claim to reduce accidents and bring in revenue at the same time. Unfortunately, when held up to scrutiny, their ability to accomplish this is ambiguous at best.

So in conclusion, I recommend the following steps be taken:

  1. The public should be provided with the raw data from the report. And I mean all of the raw data, so that an independent analysis can be conducted.
  2. Data for a control group should also be released so that the accuracy of the report can be improved.
  3. Red Light Cameras throughout the state should be immediately suspended until a more thorough investigation can be concluded, and any future plans for expanding the system to other intersections should also be halted. If 2006 and 2007 follow the same trend as 2005 we’ll save money with this as well.
  4. Delaware Legislatures should review the corrected analysis, and consider better alternatives such as extending yellow light times and using tried and true engineering principles.

I was told by the News Journal reporter that I was the first person to have brought up many of these points, and this really shouldn’t have been the case. I find this to be quite a shame. Yes, the report is long, and yes, it is boring, but this is the sort of thing that needs public scrutiny. In the mean time, call your elected public officials and representatives, call the DOT, and get the word out any way you can. The more people are aware of this the better. If anyone thinks they can help, send me an email or post to the blog.

How to Fix the Problem For free: Extending the Yellow Light

Everyone can agree that the goal of the DOT should be to decrease accidents at red lights. Unfortunately, automatic red light camera enforcement was probably the worst solution to this problem. The answer of course, is to increase the length of the yellow light. This is the only method based on sound engineering principles, its proven to work, and its free for both the state and drivers.

Mr. Svaby disagrees, and doesn’t believe it will work because “people are too impatient” and would just run the lights anyway.

Several exhaustive studies by other states disagree:

  • A study by researchers at the Texas Transportation Institute illustrates the positive safety impact of even a modestly longer yellow light. Read more…
  • The Virginia Department of Transportation noted a significant decrease in violations at an intersection in Fairfax County when the yellow light was lengthened by 1.5 seconds. Read more…
  • Critics of longer yellow lights claim there is no long-term benefit because the public will grow accustomed to the longer lights, but research shows this is not the case. Read more…

Better yet, the National Motorists Association will offer $10,000 to any state willing to accept the challenge of choosing sound engineering principles over red light camera FUD.  This won’t make up for the almos $5 Million of Delaware money sent to Nestor, but it’s a start.

File Download: DelDot’s Red Light Camera Report

Welcome to the blog

July 19, 2007


I started this blog to counter some of the FUD coming from my the red light traffic cameras as well as the State of Delaware. In the coming week, we’ll be analyzing the report published by the Delaware DOT claiming to have dramatically lowered traffic accidents at intersections equipped with red light cameras.

We’ll explore why these statistics have been done in a way that is potentially misleading, as well as the very inefficient “tax” this has placed on Delaware drivers, and where that money has actually gone.