Google is finally adding a speedometer to Google Maps on iPhone
Half a decade after it introduced the features on Android, Google now plans to add both a speedometer and speed limits detail to its Google Maps on iOS.

Google Maps on iPhone will add a speedometer
Taking an accurate measurement of a car's speed is surprisingly hard, but the vehicle's own speedometer is always going to be more accurate than a mapping app. Plus the iPhone already has speed limit warnings in Apple Maps.
Nonetheless, Google is planning to roll out the feature to Google Maps globally. As spotted by TechCrunch, the company is currently testing the feature in India. Google has subsequently confirmed that the speedometer will be available to all users on iPhone, though it did not give a timescale.
Google's current support page only mentions Android. It also, though, stresses that the speedometer figure is "for informational use only."
"Make sure to use your vehicle's speedometer to confirm your actual driving speed," it continues.
All of which makes this sound pretty pointless, but possibly the key word is pretty. For unlike a regular speedometer, the one displayed on a Google Maps screen will reportedly change color if the driver goes over the speed limit.
While the speedometer is seemingly intended to roll out worldwide, the seemingly more useful speed limits feature may not, however. Google's support page for Android refers to options "if the speed limits feature is available in your location."
It seems unlikely that Google would bring speed limits to all iPhone users before bringing it to all Android ones. For its part, Apple introduced the speed limit feature to Apple Maps in 2020, and has since been rolling it out to more countries.
Read on AppleInsider
Comments
I probably shouldn't have used the running watch example because that has to do with smoothing, rate of samples, and other factors in the calculations. My point there was that the factors and the challenges are evident at any speed. Google says "Important: Speedometers shown in the Google Maps app are for informational use only. Make sure to use your vehicles's speedometer to confirm your actual driving speed."
As Engadget points out, Waze (owned by Google since 2013) gained the speedometer function in 2016.
https://www.engadget.com/google-maps-speedometer-finally-comes-to-ios-and-carplay-185946210.html
And the article notes that the Google Maps app for Android got the speedometer five years ago.
Trains, boats, buses, and bicycles are some very common examples. Maybe you have never used any of those modes of transportation however I assure you that they are used widely through this planet.