This study led to the following lessons learned regarding each of the three technologies reviewed:

• In general, Bluetooth excels in projects of a temporary nature such as construction corridor planning, as well as targeted cordon studies that focus on the entry and exit of individuals within a selected perimeter. 
• Bluetooth can be permanently installed and is often used for real-time applications such as travel-time prediction on highways. 
• Bluetooth falls short in its ability to obtain the true OD of individual trips and is not the best technology for travel mode differentiation.
• GPS technology is highly accurate and precise, and therefore excels in studies that require detailed traces, such as network construction, travel-time and OD studies. 
• GPS often has lower penetration rates and is prone to sample bias because of its strong fleet vehicle representation. Therefore, the technology may be unable to identify wider travel behavior information.
• The widespread proliferation of MDD (e.g., location-based services (LBS)) promise a wider and less-biased view of population travel patterns, though the aggregation of data from multiple sources and the coarse temporal resolution of these data limits the precision of studies conducted at small scales.
• LBS is valuable as a supplement source. It is effective for traffic demand models and vehicle miles traveled (VMT) estimation and has an advantage in underground and indoor settings because Wi-Fi does not require line-of-sight like GPS technology does.

This study led to the following lessons learned regarding the operating agencies:

• Entirely replacing legacy data collection methods is not likely to result in the best outcomes. Rather, passive data products can be most useful to agencies that use them as a supplement to existing and ongoing data collection efforts.
• Develop consistent data validation routines to identify the inherent accuracy of purchased data products, and regularly evaluate new data purchases.
• Consider using permanent Bluetooth receivers to measure travel times between points on key corridors, especially for places where GPS and cellular reception might be unreliable, such as in canyons.
• Do not rely on permanent or temporary Bluetooth receivers to analyze trip origins, destinations, routes, or volumes outside of well-defined cordon studies or institutional settings.
• Consider using GPS data to develop a more complete picture of freight movements in and through the state.
• Develop an integrated transportation planning approach that leverage the relative strengths of household travel surveys as well as third-party OD data derived from location-based services.
• Avoid relying on a single vendor or data source for any of its analyses, rather developing processes that make use of multiple data inputs.