Because 911 was designed for ordinary landline telephones, before GPS existed, before computers existed. It's just a telephone call, not an app running on your phone.<p>Granted, it could rely on the software running on your phone to add information for the dispatcher, but not everyone has one, and not everyone who does has the same kind. And that's a good thing!<p>So it takes standardization, and government regulation. Standardization can work pretty well when there's a nice tight feedback loop with customers who are interested in the results (web browsers, for instance). How many telephone customers would switch phones based on the details of how well the phone supports 911-related features? It's not like we can test them without actually calling 911.<p>Government regulation can also work, provided you're willing to pay the costs: time and money. Lots of time, and lots of money. In fact, it costs so much for the government to regulate things like this that we end up in this exact situation. Phones have completely changed since the last 911 regulations were updated, requiring telcos to provide location information to 911 when the caller is using a mobile phone. It took years after that regulation was introduced before the telcos were compliant, and before all the local dispatch operations could use the information.<p>The same would happen today if new regulations were introduced requiring the phone itself to send this information; it would take years for anything to happen. (Though I bet Google and Apple could move faster than the telcos, they've certainly proved to be capable of that.)<p>And that's all ignoring the inaccuracy of GPS when inside of buildings, the time it takes for the phone to determine the location, etc.<p>Still, in spite of all of that, now is probably a decent time to start making those changes. It's been long enough since the last updates to the regulations, and new phones are capable enough now, that you'd have a decent chance of getting it done eventually.