Re: Stalker's dream
The data is there, but I doubt that your average city has the competence to handle that volume of data. The cell market is much larger than it was 10 years ago, and growing all the time.
You need to understand what is being collected: every time your device communicates with a tower there is an entry created in a database. The data was originally collected so that cell carriers could diagnose and tune their networks. It contains data like tower id, handset identifier, signal strength, and antenna sector. Note that it does not contain an actual handset location. But your phone will be talking to more than one tower at a time, if there are more available, so that it can choose the best tower based on strength and available bandwidth.
For a city to use this data they need location, so they can determine movement. That means matching device records from multiple towers and triangulating every device on every tower within their jurisdiction, while taking into account obstructions and topography. Then they have to overlay that on maps to get useful traffic patterns.
Imagine you have only a million handsets active in a given area, with each one communicating with towers every few seconds. You need 3 towers to get a good location. Even if you only checked every 10 seconds (which might not be often enough for traffic, depending on speed limits), you have to make 6 million calculations a minute on 18 million datapoints. Just to get the 'raw' location data. Then throw in the need to get the data from ALL carriers in the region so that you have the full picture.
It's not impossible. And I suppose the Telcos could sell anonymized data that has been pre-processed to determine locations. But its a huge task that would be pretty expensive for local governments on a budget.