What Problem Does This Solve?
Mobile users need to see their current location on a map to understand their surroundings.
Why Use This Pattern?
People that navigate indoor and outdoor spaces rely on their location to make decisions on features around them. From their point of view the world gravitates around them, they are the center of the scene with objects that are important to them showing up around them. Because mobile users are constantly moving, their expectation is that the map “follows them”. This experience is different to the usual map navigation behavior that requires the user to provide explicit pan or zoom instructions to change the extent.
When to Use This Pattern
Blue Dot is specific to mobile applications where movement and change in position of the user’s device is expected. Tracking this movement means that the user can focus on their task without expending energy to constantly pan and zoom the map to their current location. This is extremely powerful for navigation along a route so that for instance a driver can focus on the street while the application follows the car to show relevant surrounding features like traffic hazards, gas stations, and upcoming turns. Other common use cases include hiking apps and field data collection apps.
What’s the Solution?
Blue Dot is an application mode that needs to be triggered by the user, in navigation apps this is typically a button to “Start navigation”. The app then zooms to a large scale representation of the user’s current location, placing a blue dot at the center of the map indicating that this is the place identified by location mechanisms like global positioning system (GPS), mobile phone mast triangulation, indoor positioning system (IPS), internet protocol (IP) location, and/or built-in phone sensors.
As the user moves the mobile device, the map moves accordingly while keeping the blue dot centered and the pre-configured large-scale extent consistent. Under certain conditions, for instance an important intersection is upcoming, and the user needs to map to see the full scene, then this extent may change automatically. Once this condition has passed, the scale would zoom back to the default scale.
If the user interjects the navigation experience by zooming or panning the map, then the map stops centering around the blue dot and following the user’s movement. The application will show a button that reads “Re-center”, usually in the bottom left corner, that allows the user to return to the tracking mode.
Like starting the Blue Dot, the application needs a method to finish the navigation experience. This can be done by hitting the return button to back out or through a trigger like arriving at the destination. In the latter case it is advisable to popup a screen that informs the user of the fact that they have arrived, ideally by presenting additional actions that can be taken.
Any positioning is only as accurate as the mechanism available and used to locate the device. Indicating this accuracy is a useful feedback mechanism so that users know can make decisions accordingly. One way to present this feedback is through the size of the circle, the larger the blue shade around the dot, the higher the margin of positional error. Apps that also show the direction a user is facing may want to consider applying a similar mechanism to the cone of view indicator, i.e. the narrowness of the cone correlates with how well the device is calibrated for direction.
Blue dot on Google Maps now shows what direction you’re pointing; Dye, John; September 20, 2016; https://www.androidauthority.com/google-map-direction-detection-717523/ (available: 11/2/2020)