Lesson
Ensure machine vision cameras are aligned to properly detect the onset of a queue.
Experience with advanced queue detection systems in Minnesota.
01/01/2011
Intersection SH-55 and Glenwood Ave,Minneapolis,Minnesota,United States; WZ North of SH-280 and Broadway Ave,Minneapolis Metropolitan Area,Minnesota,United States; Intersection of SH-55 and Rhode Island Ave,Minneapolis,Minnesota,United States
Background (Show)
Lesson Learned
The following were recommended to ensure good system performance:
- Ensure machine vision systems accurately detect the onset of a queue. Align the camera azimuth angle with the roadway as much as possible, with respect to the location of the stop bar, even if this necessitates a reduction in the queue length detection area.
- Ensure the stop bar is visible. A stop bar must be completely visible and projected horizontally across all lanes to be monitored.
- Consider the potential for cross-lane occlusions. Monitoring more than two lanes can be problematic if the system is deployed at a lateral distance of greater than one lane from the lane edge.
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Keywords
smart work zone systems, smart work zone, smart work zones, Smart work zones, workzone, WZ
Lesson ID: 2014-00681
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