This is good stuff, and thanks for sharing. Never knew such services existed, and I will definitely try it out. If not for anything, tired of doing many of my stuffs via Google. Though won’t be surprised they also linked to Google .
Anyway I do use Google Travel sensor, and though the request is limited, I was able to manage it to achieve my aim. Which also helps me with some flexibility.
My Google API is used by myself and wife, coupled with the fact I have sensors for all modes for both of us, so that is driving, transit and walking (none of us knows how to ride a bic ).
How I do it, is that the sensors are setup to update every hour, then using automation (AD), I then have it update more frequently when it’s time for me to say leave the house to somewhere. And it will default to a particular mode, depending on what I set it to.
Even if I am out of the home, and my calendar needs me to get to another location, the app reads the location from there, sends it to the sensor and depending on the travel mode I specified in my calendar, updates the required sensor and then it and sends me notifications.
I think managing it became easier, once HA introduced the sensor.google_travel_sensor_update service.