There are lots of mobile location sharing products and many new ones everyday. Most of them appear to be centered around location check-ins and sharing with friends. While this is neat, it seems like only a small slice of the use cases in which location data is useful.
For example, lets say that I take I-66 W to work everyday, starting around 9am. If this pattern is established, and there is an accident on I-66 W at 8:50am, it would be great to know that before I start my commute. The location and time of this event is important in that if it was another road or at another time, then I really don't care to be informed regarding this event. Unless the event was at 9:30am and im running late. In order to provide context aware alerts, you need to have sufficient data in order to have a good level of confidence that a user is likely to take an action at a certain time and place.
Certainly there are existing ways to be informed regarding traffic situations. However, it seems to me that we have not taken automation regarding similar use cases yet to a usable level. Smart phones that are aways on, full of sensors and generally always with us, empower us to easily track, record, analyze and alert with minimal or no input. I've started to explore how to implement this and I hope to discuss it more over the next few days.