Wednesday, October 10, 2012

Trucking Company Questions Accuracy of Baltimore Camera Tickets

A manager from trucking company has questioned the accuracy of citations issued to them by speed cameras in Baltimore, claiming that evidence images and videos captured by the cameras shows the large semi trucks could not have been traveling at the high speeds recorded on the citations.

The Safety Manager for a PA based trucking company forwarded a citation alleging that a large semi truck had been traveling 70mph in a 35mph zone at 1300 Block of W. Coldspring Lane E/B
"This is the 6th citation we've received at this location since 1/07/12 and it's getting out of hand.  I reviewed each video personally and there was never any indication our driver was speeding.  I sent a letter to city a few months ago expressing my concerns, but heard nothing back, of course.", He wrote to us in an email.

The manager provided access to the images and videos for four violations, showing different trucks (and presumably different drivers), all recorded at the same location for various dates in 2012.  This is a company which operates hundreds of vehicles, and may have had many vehicles passing this speed camera a great many times in 2012, making the possibility of multiple occurrences of what would be a low-probability error for a single instance mathematically much more likely over that period. 

Most speed cameras in use in Maryland capture still pictures only.  However this particular camera appears to be configured to collect 3 second long video clips.  The citation images read 'speed on green', indicating this may be a converted red light camera (some red light cameras can be converted to speed cameras requiring only a software change, and red light cameras DO record video).  The four alleged violations claimed the vehicles were traveling between 59 and 70mph.  You can judge whether this is accurate for yourself.

Event #1:  The first alleged violation was on 2/10/2012 and claimed a speed of 65mph.  The image timestamps are given to 3 decimal places, giving a time interval of 0.500 seconds.  You can see from the images the distance traveled is about 1/2 the length of the trailer.  
A vehicle traveling 65mph would travel 47.7 feet in 0.5 seconds. The trailer on a typical 18-wheel semi is 53 feet long.  Half the length of such a trailer would be only 26 or 27 feet.  A trailer long enough for 1/2 its length to equate to that speed would need to be close to twice the road legal length in MD.  In addition, the second image shows a second vehicle following the truck, a portion of the vehicle is in the first image as well.  While the car is not sufficiently in frame in both images to estimate its speed, you certainly cannot conclude from this that the truck was traveling far faster than the prevailing speed of traffic.  The VIDEO captured by this camera seems to support that:

[We have blurred the video clips in order to respect the company's wish that their name and logo not be shown.  However we have the original images and citation numbers in the unlikely event that the Baltimore City government (or certain Baltimore based news outlets which don't like to talk about speed camera errors) change their mind and decide to seriously examine the matter rather than just reciting the mantra "if you don't speed you won't get a ticket".]

We have superimposed a timer over the video, so you can see the exact time it takes to traverse the length of the trailer. 

This interval is close to 1.368 s.  Assuming a 53 foot length, that would equate to about 27mph, not 65.

Event #2: The second alleged violation took place on 3/19/2012 and was for 59mph.  This also shows a time interval of exactly 1/2s.

A vehicle traveling 59mph would go 43.2 feet in 0.5s.  Once again, the trailer moved only a fraction of its length, and would seem to be only half the required distance.

Watch the video:

The time to traverse the trailer length appears to be close to 1.302s.  A vehicle traveling 59mph should have moved approximately 112 feet in 1.302s, twice the trailer length.

Event #3: The third alleged violation was on 6/5/2012 with an accused speed of 67mph.  

Same interval, 0.5s.  Same distance traveled, close to 1/2 truck length.  67mph equates to traveling 49 feet in .5s, much more than 1/2 of a 53 foot truck length.
Watch the video:

If this truck was traveling 67mph in a 37mph zone, we could reasonably assume the Toyota Prius following the truck must have been doing close to 67mph as well.  Here is the snapshot of that video.

67mph in 1.134s would equal 111feet (2 trailer lengths).

Event #4: Lastly, here's the images from 9/4/2012 accusing this truck of going 70mph... twice the legal speed limit. The time interval is shown to be the same (0.500s)

Video Frames:

70mph in .5s = 51ft.  70mph in 1.01s = 102 ft.  You be the judge.

Of course in this case YOU will NEED to be the judge, because this out-of-state company cannot reasonably contest the citations before a real judge.  And even if they did and won it would not guarantee that they (or other trucking companies) wouldn't just get more erroneous tickets later.  "We don't have a representative in the area and for a $40 citation, it wouldn't make sense to have an attorney  represent us.", the company manager wrote  "Also, I don't believe the situation with the bogus camera would be have been corrected at that point anyway."  The state high court recently ruled that contesting citations individually is the ONLY way to avoid admitting guilt, banning class actions and stating that paying the fine constituted making an "admission of speeding".  This is despite the fact that some district court judges have openly stated that they will not accept ANY argument questioning the accuracy of a speed camera's recorded speed.  The company did write to the city and reported that they received no reply.

The impact of citations sent to commercial vehicles can occasionally be more than $40 for some people.  Some professional drivers have written to StopBigBrotherMD about how they were terminated by their employers over speed camera tickets, without being given the opportunity to contest the citations.

This is hardly the first case where speed cameras have been found to produce errors with large or unusually sized vehicles.  Optotraffic speed cameras were found to have experienced "false triggers" with certain large vehicles, including in Brentwood and New Carrollton , although they work on an entirely different principal than the speed cameras (provided by Baltimore's speed camera contractor Xerox corp) which Baltimore City uses.  The town of Fort Dodge Iowa admitted that a speed camera there was issuing incorrect speed readings to trucks and other large vehicles in a location they wittily referred to as the 'Bermuda Triangle'.  Cameras in Australia have also seen errors with large vehicles, once even ticketing a bus that was 'speeding' while parked.  As such, it would seem that reliability problems measuring speeds of certain types of vehicles may not be limited to a single technology.

An even bigger problem is the fact that this camera is a rarity in Maryland because it actually collected enough evidence that it at least potentially could be used to exonerate someone.  Many if not MOST of the speed cameras in Baltimore do not provide video clips to defendants and were previously configured to display timestamps only to 1 second of precision, indicating an incorrect time interval of either 1s or 0s (even though the contractor (ACS) is quite capable of displaying the actual time interval on those citations with a minor software change).  A motorist receiving an incorrect citation from one of THOSE cameras would have absolutely no evidence they could use to exonerate themselves.  In Maryland, speed cameras are only required to be tested according to a "manufacturer specification", which might not prove accuracy under ALL real world conditions, and many jurisdictions and camera companies have taken an extremely lax view of their responsibility to verify citation accuracy using images.  One would hope that Baltimore City will not choose to "Fix" this particular problem by ensuring that future defendants never get access to sufficiently detailed evidence to independently verify citation accuracy. would like to hear from anyone who believes they have received erroneous citations.