@PotomacCyclist 7649 wrote:
Can’t they use the automated counters like the ones that are in place on other local trails? I think the Custis Trail has some of the counters. That would provide more data than just two days of manual counts.
Yes, you are correct there are automated counters all over Arlington.
The counters work using infrared beams to detect changes in temperature when a person goes past a counter. (This is either a pedestrian or biker). There are strips in the ground that detect when a wheel passes by the counter and this is how the counter distinguishes between a bike and pedestrian.
These run 24 hours a day and provide data in 15 minute increments. The problem is that they aren’t perfect. What if two joggers run by side by side? What if a jogger or cyclist is pushing a stroller or pulling a trailer? Tandem bikes? And what about places that don’t have these types of automatic counters–like along the Mt. Vernon trail where there have been numerous car accidents this summer?
The counters give hard numbers, but they still need to be “calibrated” so we have a more accurate estimate on how many bike/ped trips are being taken. Having live people count does this and also gives the opportunity to see a breakdown on rider details. Are people wearing helmets? What is the ratio of men vs. women riders?
In addition to being used here in the DC area, these numbers also go to the National Bike/Ped Documentation Project which Arlington has been a part of for the past three years. And according to our planners, the NBPDP “is generating a rich, detailed baseline of usage and exposure data to help inform transportation planning, investment, and operation decisions locally and across the country.”
Hopefully this gives you a little more insight into why these counts are important. Let me know if you have any more questions!
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