January 28


Getting Accurate Data Collection in Bad Traffic Conditions

By Mike Spack

January 28, 2016

COUNTcam, police, tdi, TMC, traffic counts, traffic data inc, turning movements

By Max Moreland, PE

What happens if you are attempting to do a turning movement count at an intersection and one of the roads is suddenly shut down because there is a police standoff one block away? This may be a bit of an odd question, but this situation happened to us here at Traffic Data Inc. just recently. Here’s how we handled an unplanned interruption in our traffic counts.

First off, we should make it clear that this traffic data is not valid and should not be used for a study. This is definitely not a “normal” day in traffic terms. The next question is then how that bad data impacts your study and what to do about it.

Traditionally in this situation, you would be sitting out at the corner of the intersection completing your count when a police officer would ask you to leave the area mid-count. Not only has your count been disrupted, but likely your schedule for the day would be too. In addition, now you have to schedule another day to come back to do the count and try to coordinate schedules with other people if completing more than one count at that time. And on top of that there’s the risk of being in a potentially dangerous situation.  Fortunately for us, we no longer have people sitting at intersections to do the counts; we do all of our turning movement counts with COUNTcams – a video based traffic collection solution.

For this particular project, we set out COUNTcams on Wednesday at this and about a dozen other intersections to record 24 hours on Thursday.  The cameras were picked up on Friday and brought back to the office to download the video.  It was at this time that we noticed the influx of squad cars blocking lanes for several hours at two of the intersections recorded.  Some quick internet searching showed it was because of a nearby police standoff (thankfully resolved peacefully with no injuries). As mentioned, because of the lane closures, any data from these videos would not be very good. Rather than needing to coordinate a lot of people, confirm schedules for a new count, and hope everything works out again, we simply needed to reset our cameras.

We were able to get in the field and reset COUNTcams the following week at those intersections without any problems.  All-in-all, we lost less than an hour of staff time in this situation compared to an entire day of setbacks had we completed the traffic counts manually. Also, since these counts were part of a larger multi-week county wide counting project, there were no delays for the overall project schedule.

Have you encountered an unusual traffic counting situation? We would love to hear from you.

  • Last October i was outside in order to make parking counts in the street of Athens. Unfortunately heavy rain started during my survey. My first thought was to go inside a coffee-shop for a while in order to avoid to getting wet my papers and myself thinking that it is a quick shower. But the rain lasted for three hours, not so heavy, but i couldn’t to continue the counts…
    So i schedule again the survey, the same day because i wanted a typical day.
    Therefore as we had discussed it is difficult to make parking counts with the countcams.
    Any idea for avoiding this kind of situation?

  • Alexios,
    As we discussed, the COUNTcams are probably not the right tool for a parking study. You could count the enter/exit vehicles to an area from videos to track the trendline of parked vehicles. We do this in parking lots when we know there are zero vehicles in the lot at midnight.

    My hunch is you could set up a tallying app on your smartphone instead of using pen/paper, but I’ve never done that.


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    Mike Spack

    My mission is to help traffic engineers, transportation planners, and other transportation professionals improve our world.

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