Transportation professionals are always looking for innovative solutions to improve their networks for the benefit of their citizens. One trending topic in this regard is data fusion between automated counters and big data.
In article one of this Big Data and Automated Counters series, we introduced big data and automated counters in transportation planning, policy, and design. We also learned about their main advantages and reviewed their drawbacks.
Now, let’s look at:
According to the Transportation Research Board, data fusion is defined as: "…the process of integrating multiple data sources to produce more consistent, accurate, and comprehensive information than that provided by any individual data source."
Automated Counters:
Big Data:
When you combine big data and automated counters, you get information that is reliable, comprehensive, and extremely in-depth. Big data gives you complex insights on your network and count data benchmarks it to make sure that everything you see is grounded, validated, and representative.
An example of isochrone analysis from Cycling Insights.
A key point that ties the two data sources together is that count data (i.e. ground-truth data) is used to inform big data and validate their outputs. On the other hand, big data brings count data to the next level with context and deeper insights.
In other words, big data can give you detailed information on your network. But, without count data to support it, this information lacks reliability and might not reflect what truly happens on your network.
When you combine big data and count data, you can:
See how the third largest city in British Columbia combined bike-share data and bike count data to estimate average daily counts on their network (case study here).
What kind of research has been done on the topic of big data and automatic counters? One study from Portland State University (PSU) tackled this topic head on.
Led by Dr. Sirisha Kothuri of Portland State University and supported by a pooled fund grant from the National Institute for Transportation and Communities (NITC), a 2022 study looked at data fusion techniques to estimate bicycle volumes for a transportation network.
The set-up for the study was as follows:
Their study concluded that, in general, adding two data sources together was more accurate than any data source on its own.
Other important takeaways:
. “… rather than replacing conventional bike data sources and count programs, big data sources like Strava and StreetLight actually make the old “small” data even more important.” .. “… low-volume sites were the hardest to accurately predict. One researcher, Kate Hyun of UTA, stated ‘We will need more ground-truth counts for low volume sites to capture the variety of locations, and that will make more robust models.” .
If you’re interested in diving deeper into this study, here are resources for you:
To end article two of this series, here are four key takeaways:
Now that we’ve gone over the combination of automated counters and big data, see our final article for an interview with a data expert on data fusion (coming soon!). Specifically, learn why combining the two sources is the key to a true, effective understanding of active transportation networks.