Previously one of the web apps I wrote provided this functionality, but Google's implementation is much better being integrated into Google Maps.
There's a number of reasons to use a feature like this. Parents can now have their children start this feature on their mobile phone and know when they're getting close. Want to let your other half know when you'll get home. Now they can watch your progress through the traffic. As a group of friends getting together, sharing your locations means everyone can see where everyone in the group is currently located. If you've ever wondered where someone was when you're waiting for them, now there's no need to wonder.
My favourite way to use such a s feature is to help a family member when they're stuck in traffic. Whilst they're focused on the traffic, I can look at the traffic on Google Maps and help determine a better route for them to take.
You can decide whether to share your location for a period of time or indefinitely.
You may find other useful ways to find this new feature.
TIP For better accuracy turn on your Wi-Fi. Google uses Wi-Fi access points around you to better locate where you are. The built-in GPS by itself is often too slow and your location can often be placed quite a distance from where you are actually located. Together, the GPS and Wi-Fi works better in built-up areas.
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