I worte about AirSage a year ago after I did some digging into their service. They contract with cellular companies to be able to pin down gps locations of cell phones. One possible application is that they get the gps coordinates of cell phones at Yosemite National Park or the Mall of America over the course of a week. Then they ping those cell phone locations a few weeks later in the middle of the night. Voila – you get a zip code distribution of where all of the visitors are coming from.
Friends of mine at Bolton and Menk are using AirSage's services to draw a big regional cordon around the Highway 10 corridor in Anoka County. They have about 30 point locations and are going to get origin/destination data over the course of a day. I believe they get the patterns broken down by hour.
Sidenote – AirSage doesn't provide data on individual cellphones. Instead they provide the anonymyzed origin/destination matrix you work out with them.
The cost for the day's worth of data is about $10,000. Of course this is a sampling method and not the hardcore license plate matching, but this strikes me as a fantastic bargain. I have no idea what the price tag would be for a video matching o-d study of this magnitude, but it would be multiples of the $10k.
This is a tool traffic engineers and transportation planners need to exploit. And since AirSage is working off of historical data, there's zero field deployment. Just a bunch of office computer work.
Here's a quick 90 second video about AirSage -