> sustain a continuous GPS feed to a 3rd-party source
Is that even a requirement? Can't you just sync every 5 minutes or so? Or sync more often when the battery is full, and sync less often when the battery is starting to deplete - given enough users that should take care of the power issue. Because it doesn't take a lot of energy to download the congestion information, so like with Bittorrent you only need a couple of seeders.
Bear in mind that you need only one data point to prove there is no congestion: a single car driving at 70 miles/hr rules out congestion at that road.
I expect it will work if all taxis are seeders, and all commuters are leeching. Considering taxis benefit a lot from such a service it's not unrealistic.
The auto-locking problem is another technical nuisance. A firmware update would fix that.
Also, I think the problem should be solved entirely without GPS. You don't want a machine to tell you that traffic is OK, what you really want is to receive a text message whenever there are traffic problems on your usual route on weekdays. "Traffic jam at intersection X" is all you need. When you get that message you just have to take a minute to figure out alternative route. The passive approach is much more appealing. After all, if traffic has been good all week you're not going to check your iPhone the next morning. Just not worth the trouble.
You could do every 5 minutes - but that would still be impossible on the iPhone, where your phone would have to remain unlocked (i.e. screen on) and your app open the entire time to do so. That is perhaps a bigger battery hog than the GPS receiver itself.
Also bear in mind that position acquisition is far from instantaneous, and has a high fixed cost. 5 minutes is probably ok, but keep in mind that your receiver is puttering away for a good minute before your scheduled check-in, just so your GPS can reacquire its position.
This would work if the software was integrated into a GPS unit, but not a cell phone. Taxi drivers in particular always have their GPS units chained to a car charger source, and this eliminates your power issue. Further, a GPS unit doesn't need to be hacked to support background applications :)
I think you misunderstand the intent of the idea - which is to use other people stuck in traffic jams to warn others who are approaching to divert. This absolutely requires a GPS unit of some sort. The data in this model is emergent, as opposed to human processed (e.g. a driver calling in an accident at an intersection).
Comments
> sustain a continuous GPS feed to a 3rd-party source
Is that even a requirement? Can't you just sync every 5 minutes or so? Or sync more often when the battery is full, and sync less often when the battery is starting to deplete - given enough users that should take care of the power issue. Because it doesn't take a lot of energy to download the congestion information, so like with Bittorrent you only need a couple of seeders.
Bear in mind that you need only one data point to prove there is no congestion: a single car driving at 70 miles/hr rules out congestion at that road.
I expect it will work if all taxis are seeders, and all commuters are leeching. Considering taxis benefit a lot from such a service it's not unrealistic.
The auto-locking problem is another technical nuisance. A firmware update would fix that.
Also, I think the problem should be solved entirely without GPS. You don't want a machine to tell you that traffic is OK, what you really want is to receive a text message whenever there are traffic problems on your usual route on weekdays. "Traffic jam at intersection X" is all you need. When you get that message you just have to take a minute to figure out alternative route. The passive approach is much more appealing. After all, if traffic has been good all week you're not going to check your iPhone the next morning. Just not worth the trouble.
You could do every 5 minutes - but that would still be impossible on the iPhone, where your phone would have to remain unlocked (i.e. screen on) and your app open the entire time to do so. That is perhaps a bigger battery hog than the GPS receiver itself.
Also bear in mind that position acquisition is far from instantaneous, and has a high fixed cost. 5 minutes is probably ok, but keep in mind that your receiver is puttering away for a good minute before your scheduled check-in, just so your GPS can reacquire its position.
This would work if the software was integrated into a GPS unit, but not a cell phone. Taxi drivers in particular always have their GPS units chained to a car charger source, and this eliminates your power issue. Further, a GPS unit doesn't need to be hacked to support background applications :)
I think you misunderstand the intent of the idea - which is to use other people stuck in traffic jams to warn others who are approaching to divert. This absolutely requires a GPS unit of some sort. The data in this model is emergent, as opposed to human processed (e.g. a driver calling in an accident at an intersection).