This is what the video detection camera sees, along with the associated zones.

Went there Tuesday to watch the video operation. The posted image is from that visit. Video detection, along with loops (embedded wires), radar, and other forms, is a balance of being sensitive enough, but not too sensitive. You and I can look at the raw video image and instantly tell what, if anything, is in the image. The video processing software is not intelligent in the form of recognizing things. It only knows that in certain areas of the image whether enough pixels have changed to trigger a detection output. It is also important to know that the image changes constantly all day, as it transitions between cloud cover and sun, for instance. The rate of change and the amount of change work together to define whether a zone has been triggered. In video, the smaller the zone, the more sensitive it is and the more prone it is to false triggering from shadows and such. The larger zones shown in the image, meant to be about "car size," are usually sensitive enough that walking through them will trigger them. A previous complaint about not seeing bicycles was the basis for the configuration shown, with two smaller rectangular zones, side by side, in the tire tracks leading up to the stop bar. Imagine a bicycle in one of the tire tracks at the stop bar. The rider plus the bicycle would take up the majority of the zone and trigger the output. On a previous visit with the same configuration I mentioned to a few bicycle riders that they could trip the light by pulling up to the stop bar. They did, it changed, and they appreciated the information. No bicycle was present on Tuesday's visit, but checking the image revealed nothing had changed. For lack of riders, I stood in the zone areas to check that it worked. It took a while, because traffic from Shore Road was constantly approaching. Eventually, it was clear that both zones in the left lane worked from just standing there. Did not put this effort into verifying the right lane because it is possible to turn right on red and it had taken about 45 minutes so far. Making the zones smaller or more sensitive comes at the price of needless signal changes, which would back up North Avenue for no reason. There is an occasional moving tree shadow problem that also cause complaints, which is beyond the software's ability to tune out 100%. As flexible as video detection is, this is one of its shortcomings, and why it is that where possible, old-school loop detectors are often a preferred alternative. The Department of Public Works has resolved this request. Thanks for helping to keep Burlington a great place to live and work.

Thanks for spending time on and explaining the issue!

Issue 4992512 has been marked as a duplicate of this issue.