Smart Cameras Blog

[From Surveillance with privacy in mind - Security Systems News]

To make surveillance more palatable, Brookline Massachusetts has installed Situcam cameras with a “physical lens cover that opens when the system is in use and closes in an obvious way when the cameras are not operational.” It is a very interesting idea, especially to convince people the cameras will not be used outside of defined times. In this case, the camera policy “mandates that the cameras only be on between 10 p.m. and 6 a.m., or during an emergency situation.”

Here is some detail on the covers:

“The covers are reassuring,” DeWitt said. “You can see the cameras are not on, and that alleviates concerns that the cameras could be remotely controlled and that the operator might manipulate them into residents’ windows or something. So having the covers makes it abundantly clear that they can’t be used for other than safety purposes.”

Are the lens covers as much for public relations as anything else? “They’re redundant,” he admitted, as the software alone can control when the cameras are on or off and who has access, “but they’re crystal clear. The teachers or town workers know there’s no chance they’re being monitored.

The lens covers and software work with many camera types (it was a Bosch system here in Brookline), and while SituCon did the integration here as one of its first big customers, Cirker said the company is looking for dealers and partners to help make the technology more widely available and known.

I am a fan of this idea and want to point out it came out of citizen involvement in polices for the use of the cameras:

How has Brookline come so far in its willingness to accept public surveillance? A lot of hard work by a citizen oversight committee that developed policies for the use of the surveillance system that made sense for the community, with a helping hand from the Constitution Project and technology provided by SituCon.

rshah Applications, Other Cities

Part 1 of this report considered accident trends in Chicago between 2001 and 2008. Part 2 focuses on accidents at traffic signals. Part 3 offers data on accidents at red light camera intersections based on IDOT data.

This part analyzes accident data obtained from the city of Chicago. The city’s study looks at 20 RLC intersections and 20 control intersections and compares them. The control intersections are supposed to be similar intersections to the RLC intersections in terms of traffic and accident rates. By using control intersections, it is possible to isolate the effect of the red light cameras from other factors affecting accidents, e.g., people driving less.

The study compares the accidents 1 year prior to the startup date to accidents 1 year after the start up date for the red light cameras. In evaluating the study, we had to eliminate 10 of the intersections, both control and RLC, because they did not have a full 12 months of prior data. This left us with 10 control intersections and 10 RLC intersections.

The control group experienced a 3.8% decrease in accidents, while the RLC group experienced a 5.3% decrease in accidents. In sum, there was only a 1.5% different attributable to the RLCs. This suggests a very small benefit for the RLCs. This decrease is a much smaller figure than the city claims.

This study was conducted entirely by the city of Chicago. The report is dated October 2007. The departments involved were the OEMC and the Traffic Management Authority. The study was not made public. I received the data after a FOIA request that required the assistance of the Illinois ACLU to push the city to release this information.

I cannot vouch for the accuracy of this study. The city picked the camera locations to study. I have no idea if they tried to “massage” the data to gain beneficial results. The city is planning a followup report due later this summer. As far as I know, they do not having any impartial experts involved in the process. I hope the city’s analysis will be fair, rather than manipulating the data to justify the effectiveness of the red light cameras.

rshah Chicago, Red Light Cameras

Part 1 of this report considered accident trends in Chicago between 2001 and 2008. Part 2 focuses on accidents at traffic signals. This part focuses on accidents at 39 red light camera (RLC) Intersections based on Illinois Department of Transportation (IDOT) data obtained via the Chicago Tribune. The accident data is publicly available here.

The results show that accidents went UP 5% at the intersections with RLCs. This is a shocking result, because you would expect accidents to decline with the introduction of RLCs. The results also stand counter to the general trend of accidents falling at in Chicago about 7% between 2005 to 2008, as well as the 7% drop of accidents at traffic signals.

Results:

The simplest analysis we did was to look at accidents 1 year prior to the startup date and compare it to accidents 1 year after the start up date for the red light cameras. We found a total of 1118 accidents at the 39 intersections 1 year prior to the startup of the RLC. We compared this to 1 year after the startup date and we found a total of 1192 accidents. So in first year the RLCs were used, accidents as a whole went up at the RLC intersections!

We also used a longer time period, which varied according to the data we have for the individual intersection. The longer time period varied from 347 days to 1080 days with a mean of 500 days. This data also found an increase 4.5% in the number of accidents.

We examined the data to see if there was any “bumps” or changes in red light accidents over time. For example, was there an immediate decrease in accidents and then accidents went back up after 3 months? We found that the rate of accidents was constant at intervals of 1, 3, 6, 9, and 12 months.

Unfortunately, we don’t have access to the entire data set (without manually entering in the Tribune data), so we can’t perform a more sophisticated analysis, such as whether there were changes in the types of accidents (angle & rear end) at RLC intersections.

There are two sources of data on accidents at the RLC intersections. The first is from the Illinois Department of Transportation (IDOT), which is used here. The second is from Chicago’s Department of Transportation (CDOT). Accidents at intersections are measured differently by both agencies. CDOT defines the intersection as extending along the arterial street for a distance of 25 to 50 feet while IDOT will use measurements of 150 to 300 feet. Despite the differences in measurements, we believe any tanglible affect of RLCs should be found at either distance.

The startup dates for the cameras varied from January 1, 2006 to Nov 26, 2007. The analysis compares accidents in the year prior to the installation date to one year after the installation, e.g., for a camera installed on April 1, 2006 the year prior data is from March 31, 2005 to March 31, 2006. The year after is April 1, 2006 to April 1, 2007.

rshah Chicago, Red Light Cameras

[From The Associated Press: NJ city leading way in crime-fighting technology]

East Orange, NJ is a city with high crime that has decided to fight crime with new leadership and technology. The question is how much credit is due to the technology. The AP article highlights some of the technologies East Orange is using:

• Database for crime data instead of using paper reports
• Wireless computer system for all patrol cars
• Video surveillance cameras in high-crime areas
• Virtual community patrol system for residents to report crimes via text message
• Grid showing patrol cars’ locations
• Gunshot detection system that tracks the source of shootings.

The article next mentions the next generation smart camera technologies that East Orange is adopting:

The sensors, which work in concert with surveillance cameras, are designed to spot potential crimes by recognizing specific behavior: Someone raising fist at another person, for example, or a car slowing down as it nears a man walking on a deserted street late at night. Each new crime recorded is programmed into the database.

“They know what is normal behavior,” said Tarik Hammadou, whose Australian company, Digisensory Technologies, makes the sensors. “And when there is abnormal behavior like an assault, we annotate it and say to the sensor, ‘This is an assault,’ so the sensor will always remember the pattern.”

When the sensor raises an alert, an officer sitting in the department’s nerve center can zoom in on images to see if a crime is in progress. A computer program sends the information to a laptop in the patrol car nearest to the scene. The whole process takes seconds

As the article notes, the effectiveness of these technologies is questionable.

rshah Other Cities, Vendors

Part 1 of this report considered accident trends in Chicago between 2001 and 2008. This part focuses on accidents at traffic signals. The theory behind red light cameras is that people will drive more carefully at intersections. If they are driving more carefully, we should expect accidents to fall across all traffic intersections, not just the ones with red light cameras.

Here are the main points:

1. Accidents at traffic signals are down, but once we account for the general drop in accidents, the accident rate at traffic signals is holding relatively constant. (There is no halo safety effect from the red light cameras on accidents.)

2. There appears to be a steady drop in Angle crashes over the last 5 years, indicating that there is a change in behavior at traffic signals.

First, consider the overall trend in accidents at traffic signals:

A quick look at this graph shows that it is very similar to the overall drop in accidents. To factor out the general trend of accidents dropping, we next determined the percentage of accidents that occur at traffic signals in Chicago between 2001 and 2008.

This graph shows that the percentage of accidents at traffic signals hasn’t changed appreciably between 2001 and 2008. If people were driving more carefully at traffic signals, it would be expected that accidents at traffic signals would become relatively rarer. For example, dropping from a share of 25% of all accidents to 20% of all accidents. The results here suggest that traffic signal accidents are holding relatively constant. This also suggests the RLCs are not having a halo effect because accidents are not dropping throughout the city at traffic signals.

The next step was to consider the types of accidents occurring at traffic signals in Chicago between 2001 and 2008.

The biggest finding here is the drop in Angle crashes (crashes where cars are heading in different directions). Between 2003 and 2008, there is a 5% drop in Angle crashes at traffic signals. This is a large! This drop supports the argument that red light cameras are leading drivers to be more careful at traffic intersections.

For both turning and rear end type crashes, their was little change with the exception of the 2008 numbers. Hopefully, 2009 numbers will identify if there is a trend in an increased share of rear end accidents and a decreased share of turning accidents at traffic signals.

This data was obtained from the Illinois Department of Transportation (IDOT). IDOT has a separate variable for traffic signals in their accident data.  This allows us to isolate accidents that occur at traffic signals.

rshah Chicago, Red Light Cameras

The is the first of a series of posts on report on red light cameras in Chicago.

The two important points:

1. Accidents are down 21% between 2001 and 2008, largely due to people driving less.

2. Any analysis of accidents needs to account for this trend. This trend suggests fewer accidents at construction zones, school zones, highways, and traffic signals (EVERYWHERE). If you are suggesting anything has contributed to safety, e.g., red light cameras, you need a control group to identify the contribution of the safety device or program. Otherwise it will appear that red light cameras have led to a drop of 20% in accidents (when the drop is due to other factors).

Lets begin with a graph of accidents in Chicago between 2001 and 2008:

Clearly there has been a decline in accidents (over 21% between 2001 and 2008). There are a lot of factors affecting accidents from gas prices to the weather. One factor that can be taken into account is how much people drive. The IDOT provides an Annual Vehicle Miles of Travel statistics that allows us to account for how much people drive over a year.

The graphs shows that vehicle miles have dropped in Chicago from 12.6 billion miles in 2002 to 11.6 billion miles in 2008. If people drive fewer miles, it seems reasonable that there will be fewer accidents. We can analyze this by looking at the accident rate for each mile traveled.

This graph shows when we take into account the fewer miles driven in the city, there is no longer a steady drop in accidents. Instead, it’s hard to find a significant trend between 2001 and 2008. It’s also important to note that you can find either a trend of accidents going up, down, or holding steady depending on the what years you include. So once we account for people driving less, there is not a steady trend of accidents dropping.

rshah Chicago, Red Light Cameras

My red light camera study is going public this week, you can see TV coverage over at FOX – New Analysis Shows More Crashes at Intersections With Red Light Cameras.

A longer description can be found at The Expired Meter. I will provide the full report in a few days for everyone.

rshah Chicago, Red Light Cameras

[From The Daily Northwestern - Evanston’s surveillance camera plan stirs mixed reactions]

A nice article on the discussions to install cameras in Evanston. I talked to the reporter and shared some preliminary insights in our research on the relationships between crime and cameras in Chicago. Read the article if you want the insights, otherwise by late summer, Jeremy and I will have the paper ready to share.   

I am working on statistical results/reports for this study and a red light camera study that will be released in early June. Sorry for the slow down in postings.

rshah Other Cities

[From Security Info Watch via Crain's Chicago Business]

The Chicago Police Department is pushing for the use of 200 cameras along interstate highways between Chicago and Mexico. The cameras would be fitted with ALPR technology, allowing them to identify suspicious cars. This would become the nation’s largest interstate police camera surveillance system. Specifically, the project would include “192 stationary cameras covering roughly 1,200 miles of highway across 13 states and connected to 50 mobile license plate recognition systems in vehicles.” The data that comes out of this will be immense:

Pictures of license plates and the rear end of vehicles would be time-stamped with GPS coordinates and fed into a computer that would compare them against local or national hot lists of suspect vehicles, with the information shared by participating agencies. In addition, the data would be used to analyze trends and develop patterns of travel by vehicles suspected of trafficking contraband between Chicago and the border of Mexico, according to the proposal.

While the original purpose is to identify trends in vehicles carrying drugs, the data could be used for much more. The eight page proposal can be found online at Scribd.

rshah ALPR, Chicago

[From Chicago's $1.3 Million Experiment in Democracy: Participatory Budgeting in the 49th Ward]

The 49th Ward, home to over 60,000 people and the neighborhood of Rogers Park, is known for its diversity and vibrant community life. Over 80 languages are spoken within less than two square miles. Independent-minded citizens have often put intense pressure on local officials. Concerned that Moore wasn’t responding to ward needs, they nearly voted him out of office in the last election. So how does one of the nation’s most diverse neighborhoods bring opinionated residents together to make difficult budget decisions?

Moore started by setting aside his $1.3 million “menu money,” the discretionary budget that each alderman receives for capital infrastructure projects.

. . .

The Public Safety Committee, for instance, received many requests for security cameras. To learn more, they visited the neighborhood’s 24-hour camera viewing center. As community representative Marilou Kessler explained, “everyone [on the committee] came—about 15-16 people on a workday. It was astonishing cooperation.” The trip shifted the committee’s priorities: They learned that the cameras are used only occasionally, mostly by specialty police teams, and are not continuously monitored. After police explained that lighting is more effective at deterring crime, the committee replaced several camera proposals with street light proposals. (my emphasis)

It appears the CPD thinks that lighting is more effective than cameras!

rshah Chicago